Lacking intimate acquaintance with the earlier movies of John Waters, I can't compare his wittily titled "Polyester," now at the Key in Georgetown, with the outrages that made him a notorious cult favorite, notably "Pink Flamingoes." I gather that the new film, a fitfully amusing and perfectly harmless spoof of the morbid and masochistic cliches that sustain the typical soap opera, represents a mellow, spruced-up turn toward the mainstream.

I'm inclined to believe that it must also represent a change for the better.

The public that enjoys overrating tackiness and facetious amateurism may be conforted by the dead spots and atrocious bits of acting in "Polyester," indicating that Waters isn't operating a completely professional sideshow yet. However, he specializes in a form of depraved, deadpan burlesque that can only be enhanced by better acting, timing and production values.

Waters never really improves on his opening sequence, a bogus instructional prologue designed to introduce Odorama, a scratch-and-sniff promotional gimmick. Discovered in a laboratory, a Germanic scientific authority called Dr. Arnold Quackenshaw expounds on the wonders of this olfactory breakthrough and explains how to use the special Odorama card. A flashing number in the lower righthand corner of the screen cues spectators to sample one of 10 numbered circles on their cards as the movie unreels.

Quackenshaw is impersonated to fanatic perfection by an actor who remains inexplicably uncredited. The entire sequence is deftly realized, a cheerful exaggeration of all such pseudo-scientific hokum. Waters gives Quackenshaw a wonderful line of malarkey: "Through this nose come some of life's most rewarding sensations . . .However, you may experience some odors that will shock you. This film's producers believe that today's audiences are mature enough to know that some things just plain stink." For a crowning touch, the screen frame expands as Quackenshaw exults, "This is Odorama !"

A funny literal-minded come-on, Odorama is never a significant enhancement to the plot or imagery. The distinctive range of orders is pretty much exhausted after numbers 1 and 2, meant to evoke a rose and a blast of gas from the herione's crude spouse, respectively. Essentially superfluous, the card is easy to set aside and forget about. The heroine, an oppressed housewife from suburban Baltimore called Francine Fishpaw, embodied by Waters' most imposing "discovery," the obese female impersonator known as Divine, is supposed to have an extremely sensitive nose, but the smells aren't associated with particular characters or crucial melodramatic revelations.

Asking only contentment and respectability, Francine gets nothing but grief and contempt from her vicious family circle. Husband Elmer (David Samson) is a shameless sleaze, the owner of a porno movie theater at a shopping center, Crockfield Mall. The Fishpaw residence is the target of protesters demanding a change in exhibition policy ("Please show G-rated movies, please show 'Benji'!" pleads one pathetic tyke), but the demonstration that humiliates poor Francine is relished by the boorish Elmer. d

The Fishpaw children, Lulu and Dexter (Mary Garlington and Ken King), are already slaves to vice. Lulu, a squealing, pelvis-shaking morsel of jailbait, consorts gleefully with young hoods and turns tricks during lunch hour at high school. (Garlington's ants-in-the-pants vibrations are very funny -- the teen equivalent of Carol Burnett's Charo impersonation.) Dexter, an insolent little creep who affects a punk look, is addicted to sniffing glues and cleaning fluids. He's also a foot fetishist and the obvious suspect as the dread Baltimore Foot Stomper, the scourge of innocent shoppers.

Francine's only solance is her ex-maid, Cuddles, who has inherited a fortune from another employer and lends a synmpathetic ear whenever she visits. Waters has tailored the role of Cuddles for his most borderline discovery, a squat, snaggletoothed Baltimore bag-lady named Edith Massey. In "Polyester" she's deployed as a weirdly derelict model of refinement. Waters throws her lines like "Ooooo, a Halston, how au courant !" and "What's the matter, mon petite ?" Her rather alarming appearance is softened to a remarkable extent by the director's affectionate acceptance of he oddness. Waters seems so relaxed with Massey's imperfections that the instinctive repulsion eventually fades away.

On the brink of dispair, Francine is rescued by a passing dreamboat, a middle-aged playboy named Todd Tomorrow, played by Tab Hunter. Like Elmer, Todd is an exhibitor, but his standards, are hilariously elevated. The wittiest single idea in the script is Todd's theater, a drive-in that caters to foreign film snobs. The program is a Marguerite Duras triple bill, and the patrons arrive in formal dress to partake of caviar and champagne at the posh concession counter. Divine has a priceless throwaway take during this merry sequence: leafing through a copy of the French periodical Cahiers du Cinema in the lobby, Francine reacts with a shrug of bafflement.

"Polyester" tends to belabor a premise ridiculed much more incisively and consistently by the Carol Burnett company in its recurring skit "As the Stomach Turns." In a similar respect, Divine's extended drag performance seems to count for less than Harvey Korman's brief, astonishing turns as a massive Jewish mama. (What a pity the Burnett show closed before she got a shot at the Mary Tyler Moore role in "Ordinary People!")

Not that the Waters gang doesn't have its moments. Anyone who grew up giggling at the idealized prototypes "Polyester" mocks may find a reasonable amount of the mockery amusing. Still, it's difficult to surpass the unintentional humor of the phototypes themselves. Divine in "Polyester" isn't remotely as funny as, say, Connie Stevens in "Susan Slade" or Lana Turner in "The Big Cuse." Now those were irresistible stinkers! l