Paul Newman's latest taste of success

As every salad-lover knows by now, Paul Newman has bottled his ''house'' dressing and is marketing it under the name ''Newman's Own.'' The ingredients seem to consist of perfectly ordinary soybean oil and vinegar, with a little dehydrated onion and garlic for flavor - plus, of course, a smiling picture of himself on the label. And for that little extra, ''Newman's Own'' sells for 20 to 75 cents more than other dressings concocted by plump, shifty-eyed chefs with names like Charlie or Jake, who put their portraits on their labels at their own risk.

There are rumors in the film capitals and the great kitchens of the world that Robert Redford is about to come out with a mustard known as ''Redford Hot.'' The story has been neither confirmed nor denied. But surely other stars who have managed to stir a packet of instant cocoa in a mug of hot tap water without a major accident will now be emerging from the kitchen with a product line for the groupie-gourmets.

It should be sort of inspiring to see a celebrity peddle his own salad dressing (or whatever), instead of holding up somebody else's label to the television camera and doing the standard sincere endorsement. In this day and age, how many people ever get rid of the middle man?

Still, a lot of people find it hard to understand why Mr. Newman would dirty his hands with salad dressing - literally, if Joanne Woodward is to be believed. Her husband, she says, finishes off his spicy gift to the greens by giving it a stir or two with his fingers.

Even the Laffer-curve economists who think profit incentive is all cannot imagine that Mr. Newman bottles ''Newman's Own'' for the money.

Is Mr. Newman producing salad dressing to enhance his image? But if so, how? His other hobby - auto racing - adds to his actor's aura of machismom . But just what does stirring vinegar and oil with your bare pinkies do for a chap?

A number of Newman-watchers have noted that the new salad-dressing tycoon has always confessed to a yearning to play the clown - almost as strong as the yearning of most clowns to play Paul Newman. It gets boring - we're merely supposing - to win all those beautiful ladies, to say nothing of those auto races. In lieu of the proper Hollywood vehicle, has Mr. Newman written his own script for himself? - Charlie Chaplin duckwalking between vats of oil and vinegar in the old salad-dressing factory, his stirring fingers at the ready.

The frustrated-comic explanation is a beginning. But does it tell the whole story? What this salad-dressing business says to us is that Mr. Newman wants to escape not just the role of leading man but the whole realm of make-believe.

He is Prince Charming, applying for a job in the castle kitchen.

After 35 years as a two-dimension fantasy, the poor man is begging to be allowed to climb down from the silver screen and become part of the audience - those real folk who get popcorn stuck in their uncapped teeth while, with linty paper napkins, they wipe their earthy peasant lips.

And speaking of popcorn, we have learned that this may be the next product to bear the label, ''Newman's Own.'' Mr. Newman, according to friends, is famous for his flawless home-popped kernels, blended from the corn of three elite hybrids.

What with salad dressing and popping corn, Mr. Newman may never get out of his kitchen again. We wish him all success in his new dream of finding happiness over a mixing bowl and a hot stove.

In case life, as it sometimes does, requires a trade-off, we know one terrific fast-food chef, with an absolutely smashing profile when he stares at a well-done hamburger to his left. We trust Mr. Newman will wipe off his oily fingers long enough to write the proper letters of introduction.