By Steven Rosen

LOS ANGELES -- Leave it to John Waters to see the sexual possibilities of a blow to the skull.

The debonair and perversely witty director of such films as "Pecker," "Hairspray," "Cry-Baby" and "Serial Mom" just happened to be reading a medical article on concussions that noted such accidents can produce carnal lust in some victims.

Before he could shout "Kinsey!" the idea for "A Dirty Shame" was born. In this NC-17 comedy, so rated because of its pervasive sexual language and subject matter, a group of such "sexcussion" victims battles the anti-sex "neuters" for control of a drab, working-class section of Baltimore, Waters' hometown and the site of his films. The Fine Line Features film gets its national release Friday.

At the heart of the battle is Sylvia Stickles (Tracey Ullman), a dowdy, grumpy homemaker who - after a freak accident - becomes an out-of-control sex addict whose lewd dancing at a nursing-home party shocks the community. Especially since her gruff, charmless mother Big Ethel (Suzanne Shepherd) is a leader of the neuters. ("Tolerance went too far, and we all know it," Big Ethel likes to shout.)

Waters populates this slice of rundown Americana with virtually every weird (yet real) sexual fetish he could find, although he eschewed violent ones. So we get "sploshing" (people who dump food onto their erogenous zones), Roman showers (people who like to vomit during sex), "adult babies," gay "bears" (heavy, hairy men attracted to one another), men attracted to geriatric women, and so much more.

During a recent interview here, Waters says he has been preparing for "A Dirty Shame" since boyhood, when school nuns warned him he would go to hell if he saw smutty sexploitation movies popular in the 1950s. That turned him on. "So I got obsessed by those movies, and I'd pretend I owned a dirty movie theater," he says.

"When you're brought up to think sex is dirty, it will always be better," Waters says. "Sex can't be that wholesome, or it gets really boring. It was more fun to me when gay was illegal. I'm glad it isn't anymore, but just think: Every time you had sex you broke the law - that was a certain fetish right there."

The film also features Selma Blair as Ullman's daughter - nicknamed Ursula Udders - who has to be locked away to keep from being arrested for exposing her stupendously large breasts at the local bar. And it has Johnny Knoxville as the long-tongued leader of a "carnal rapture" religious cult whose call of "Let's go sexin"' has a seductive, prophetic quality.

This might sound like a return to Waters' raunchy roots - as an underground filmmaker working with the late female impersonator Divine - whose 1972 "Pink Flamingos" was an arthouse shocker. Other ultra-outr頗aters films include "Multiple Maniacs," "Female Trouble," "Mondo Trasho" and "The Diane Linkletter Story."

He has become a far more mainstream figure lately, with "Hairspray" adapted into a hit Broadway musical. "Cry-Baby" also is slated for Broadway.

But Waters says he never really wandered that far from using sex - and shock-effect tastelessness - as a satiric weapon. Indeed, during a recent interview, he seemed to get the same kick from it that Cole Porter once got from champagne.

"I don't think it's a return" to the earlier films, Waters says of "A Dirty Shame." He's having a great time firing off quick-witted replies - like a lithe tennis player returning volleys - to a small group of writers trying to keep straight faces while asking about the societal prevalence of strange sexual fetishes.

"Cecil B. Demented," his last comedy, about teenage terrorists, had a sexual joke involving a gerbil, he fondly recalls, as well as a porn-theater scene, he reminds us. "In 'Pecker,' there were close-ups of a giant pubic hair," he says. "I don't know if this is so different, except for the rating. And because it is about sex, it's a more volatile subject matter."

At 58, Waters is an energized and amusing figure. He leans into questioners when answering questions, sometimes putting his hand on the back of the nearest chair. His replies have a winningly confessional quality that is part heartfelt and part theatrical presentation. Trim with neatly combed graying hair and a famous pencil-thin mustache, he is an elegant, retro-cool dresser.

On this day he wears a tie and blue shirt under a black sport coat overlaid with resplendent red-and-white-outlined rectangular patterns. It looks like something one of his beloved rockabilly singers, Johnny Burnette or Jody Reynolds, might have donned.

"Rockabilly I've always liked - it sounds dirty to me," he confides. "I've had it in a lot of my movies." (It's featured in "Dirty Shame," along with risqu頯ld party songs like a female version of Doug Clark and the Hot Nuts' "Hot Nuts.")

"A Dirty Shame" is not meant to pack a message per se. As sexual satire, it aims to skewer both the squares and the hipsters, although perhaps the hipsters more lovingly than the squares. While certainly not conservative, it makes fun of permissiveness too.

"Today, the words Lenny Bruce went to jail for are on sitcoms, so it certainly is freer than it's ever been," Waters says. "I don't think this movie is saying we're repressed. I'm questioning how far can freedom go. Can tolerance go too far? Do we really care about the rights of 'adult babies'? I don't know if I do, to be honest. There seem to be a lot of causes; when does it become the last cause?"

Waters is glad the "Dirty Shame" cast had a sense of humor, given the crudeness of what he foisted on them. The Hollywood actors are deflating their star egos, to some extent. And the many comparatively homely people with small parts - most would never be confused with a Hollywood star - get a shot at a kind of fame. They're in an "infamous" John Waters movie!

"That's what my movies are about - how much fun it is to be famous, in a weird way," Waters says. "I have no patience for people who complain about that. Nothing bad has ever happened to me, except I can't go to sex bars because people say right in the middle, 'I liked "Female Trouble."'That puts a real damper on it."

(This story originally appeared in the Denver Post.)