If your idea of fun is Tracy Ullman crouching over a bottle of water and picking it up with her vagina, then you'll love A Dirty Shame. It's all about head trauma and sexual perversion, see. Ullman is Sylvia, a harried suburban shmoe with a horny hubbie (Chris Isaak) who's reduced to knocking 'em out over grumble mags in the bathroom. Their daughter, a Zeppelin-chested stripper (Selma Blair), is locked away upstairs for her own salvation. But then Sylvia gets a bop on the head and the carnal demon within squirms out, midwifed by Johnny Knoxville's supernatural sex guru.
There are one or two unstrained dialogue laughs ("My clitoris is in crisis!") and Ullman is a good sport, playing horny Sylvia as a staggering, nympho sex-zombie on permanent comedy-heat. But helmer John Waters' trash-to-glitter formula feels more sloppy than schlocky, with Blair's back-breaking, ski-slope gazongas the most striking stand-out.