THEY’VE GOT A SECRET : These days, it seems as though everyone has something to hide.

The subject was secrets, and those people in Ventura County who keep them. The questions were addressed to mustard-makers and military men alike, and the responses were all over the lot.

The Jack-In-The-Box manager was startled. The phone company spokeswoman was amused. The confederates of David Murdock were not.

Jonathan Trusty, aspiring magician, let slip a little about the old floating bill trick (static electricity is involved).

The California Highway Patrol offered up a stack of numbers.

And the FBI, after telling us next to nothing, called back to find out when our story would run. We refused to tell, on the theory that there must be a principle at stake in there somewhere.

Now, let the interrogation begin.

Exactly what goes into those vats in Oxnard where they brew Grey Poupon mustard?

Some 214 years after the first Grey Poupon was mixed by Mr. Poupon and his partner in Dijon, France, Nabisco’s Oxnard plant produces all the world’s Grey Poupon, an estimated 30 million jars a year. Each includes vinegar, mustard seed, water, salt, kosher white wine and a few herbs and spices. But that’s not really what’s important.

“The secret,” said Nabisco spokesman Mark Gutsche, “is the formula. I don’t know the formula. The plant manager doesn’t know the formula. He gets pre-blended spices.”

In fact, said Gutsche, not one of the Oxnard operation’s 100-plus employees knows the precise Grey Poupon formula. Among 32,000 Nabisco employees around the world, Gutsche said, about four know the formula. They are all at the company headquarters in Parsippany, N. J.

“They’re kind of technical gee-whiz types,” said Gutsche. “Guys in white coats.”

What’s the Federal Bureau of Investigation working on in Ventura County right now?

FBI spokesman Fred Reagan took the call, listened to the question, and asked if he could call back. Five minutes later the phone rang, and Reagan handed the question over to Agent Karen Gardner. Agent Gardner said hello. Agent Gardner acknowledged that the FBI has about a dozen agents assigned to its Ventura office. Agent Gardner said she would be happy to discuss what they were doing.

“But if we tell you,” said Agent Gardner, “we’ll have to kill you.”

Who has Ventura County’s unlisted phone numbers?

“I could tell you,” said Pacific Bell spokeswoman Katie Flynn Jacobs, “but then I’ll have to destroy your phone.”

She denied any connection with the FBI.

As for the phone numbers, she said: “If they’re unlisted, they’re under lock and key. They’re not even in the database. Somewhere, somebody has them, but there’s a very involved security procedure in limiting the access to those numbers.”

Thirty-eight percent of California’s residential phone numbers are unlisted, Jacobs said. That figure has risen steadily, she added, even though the anonymity currently costs customers an extra 30 cents per month per line.

What is David H. Murdock worth?

Murdock heads a firm that is developing the high-priced estates and country club at Lake Sherwood and keeps a weekend estate of his own in the area. As the top officer of the mammoth conglomerate Castle & Cooke and scores of private companies, he is widely regarded as the wealthiest human being in the county.

According to figures gathered in a survey by The Times earlier this year, Castle & Cooke paid Murdock $1.3 million in salary and bonuses during the 1989-90 fiscal year. Last October, Forbes magazine estimated Murdock’s worth at $1.35 billion.

We wanted to ask Murdock for his own estimate, but his phone number wasn’t listed. Instead, we reached his office at Lake Sherwood and asked if Forbes was accurate.

“To be honest, I don’t have the faintest idea,” said spokesman Steve Seemann, speaking for Murdock. “I’m not sure he knows, to be honest. . . . Mr. Murdock owns a lot of real estate. What’s real estate worth?”

Are they still using Secret Sauce at Jack-in-the-Box, and what’s in it?

“We do use Secret Sauce,” confirmed Mohammed Ahmet, manager of the Jack-in-the-Box on Daily Drive in Camarillo.

The ingredients?

“If you can come in, I can give you the nutritional information. It’s supposed to be secret, but everything that’s in it is right there in the nutritional information.”

Where’s the California Highway Patrol’s favorite Ventura County speed trap?

“I have no idea,” said CHP spokesman Jim Utter. “I really don’t. I’m being honest with you. I’ve been out of the field for about five years now. . . . I’m being honest with you.”

Utter did note that on the Ventura Freeway in 1990, patrol officers were most productive on the Camarillo-to-Oxnard stretch.

CHP figures, which exclude big-rig trucks but include all other speeding tickets, show 4,275 citations between the Los Angeles County line and the summit of the Conejo Grade; 4,959 between the Conejo Grade and Vineyard Avenue in Oxnard; 2,061 between Vineyard and Seaward Avenue in Ventura, and 3,288 between Seaward and the Santa Barbara County line.

Most patrol officers, Utter said, make no attempt to conceal themselves.

Does Ventura County Municipal Judge Lee E. Cooper keep a gun under his robes in court?

Cooper holds a special county permit that authorizes him to carry a concealed gun, and the judge says he has been a target of threats in years past. In January, he declined to say whether he carries a gun on the bench, but did say, “I think it would be reasonable for a judge under the appropriate circumstances to do precisely that.” Six months later, he was still mum, and suggested that the issue was “a dead horse.”

Which prominent Venturans wear hairpieces?

Brad Helton, owner of Hair Pieces on Thompson Boulevard in Ventura, said he has sold hundreds of hairpieces in his 27 years in the business, including more than one to a man who was a local newscaster. It’s been more than three years since Ventura has had a local newscast, however, which limits the man’s celebrity status.

There was also the brother of the famous actor, R . . . “But you’re writing this, right?” asked Helton. “I’d be a little reluctant to discuss that.”

Local politicians? None are sporting store-bought hair, as far as Helton knows, “but there’s some that could use some. I wouldn’t want to completely rule them out.”

For those who do favor hairpieces, Helton urges against secrecy, especially in romantic relationships, because “the woman always finds out. Maybe the guy puts it on crooked. Maybe during a frenzy of making whoopee, something happens . . . and then she knows something that he has been deceptive about.”

How does the old Floating Bill trick work?

“I borrow any denomination bill from the audience, and put some static electricity on the bill from my leg,” began Jonathan Trusty, 27, vice president of the Camarillo chapter of the Society of American Magicians.

It’s Trusty’s best trick. He learned it about five years ago and shows it off on nights and weekends, when he’s not working as a technical services manager for The Gap clothing stores. He will be performing six shows daily at the Ventura County Fair on Aug. 16-18.

Back to the trick: Trusty twists the bill into a sort of ball, lays it on his hand and watches along with the audiences as the bill seems to flicker with static electricity.

“And then all of a sudden it actually rises from my hand, and it’s free-floating in the air.”

But static electricity is not the key to levitating a bill. How exactly does Trusty do that?

“Very well, thank you.”

What is Nicholas Scanlan’s mantra?

Scanlan, 38, started studying Transcendental Meditation 20 years ago as a student at the University of Minnesota. He is now director of the International Meditation Society’s Ojai office, dispensing mantras to new students and offering courses at $400 for adult individuals and $600 for families.

A mantra, Scanlan said, is a private word, usually four syllables or less, that a meditator repeats internally to relax and reach a state of pure consciousness in which “the mind stops its incessant chattering.” If students reveal their mantras, Scanlan said, “they’re immediately disintegrated, as soon as they pronounce it out loud.”

Transcendental Humor there. If a student spills his or her mantra there’s probably no harm done, Scanlan said, but a brush-up course in meditation technique is probably in order.

Over the last 25 years, Scanlan said, more than 5,000 Ventura County residents have taken the Transcendental Meditation course, each receiving a mantra tailored to fit his or her age, occupation, educational background and other factors, such as whether he or she was on medication. The mantras are usually four syllables or less. And Scanlan’s?

“Ha ha ha ha ha. Right .”

What’s the Navy doing behind all that barbed wired in the high-security center of its Port Hueneme base?

“We’re doing the same work we’ve always done,” came the non-answer from Russell M. Pyle, public affairs officer for the top-secret Naval Ship Weapon Systems Engineering Station (a.k.a. Nemesis). “We’re the in-service engineering agent for the Navy’s surface warfare combat systems. . . . And that takes in a lot of different responsibilities.”

Among them are Tomahawk, Terrier, Tartar and Talos missile systems, as well as the Navy’s most advanced combat system, Aegis. That system, which specialists are still adding to selected ships, uses elaborate computer software to coordinate split-second responses to air, surface and subsurface threats.

The Nemesis organization’s annual budget is estimated at $300 million, and its military work force is put at 2,300.

Given its mission, budget and number of employees, you could consider the Navy the biggest secret-keeper in the county. And Nemesis is its biggest secret, right?

Pyle referred the question to Nemesis security officer Rod Franz.

“That,” said Franz, “is information I can’t divulge.”