The 1972 scandal of Pink Flamingos, in which Waters had Divine nibble on dog feces, is now a tame stunt on Fear Factor. No matter. A Dirty Shame is Waters unleashed, and wicked, kinky fun for anyone except the twits who rated it NC-17. Tracey Ullman tears it up as Sylvia Stickles, a middle-age frump living with her sex- ved husband (Chris Isaak) on blue-collar Harford Road in Waters’ native Baltimore. Sylvia is a schlump, but you just know that something’s up when Waters weaves in the song “Sylvia,” from a gorgeously tawdry 1965 Carroll Baker flick. One car accident and head concussion later, Sylvia has her legs in the air and is begging to have her labia licked. The first obliging stud is Ray-Ray (Johnny Knoxville, indulging in tongue action you never saw on Jackass). Ray-Ray is the leader of a sex-addict cult (all head-injury victims) and all hellbent on saving the world from sexless neuters. That might explain why Sylvia’s daughter Caprice (the sublime Selma Blair) sexes up with breast implants that make Anna Nicole Smith look like Kate Moss and strips under the name Ursula Udders. It doesn’t explain how Sylvia (dancing in a nursing home) manages to pick up a bottle with her vagina. But who wants explanations from a movie where even the trees take on the shape of hard-ons? You may even shed a tear when Sylvia bonds with her daughter by confessing, “I’m a cunnilingus bottom.” OK, the jokes are hit-and-miss and the plot is nonexistent, but the Waters spirit stays consistently and sweetly twisted. When the cast takes to the streets singing, “Let’s go sexin’,” you want to cheer them on.