Joe Dirt, starring David Spade as a redneck janitor who digs food and clothing out of Dumpsters, has been rated PG-13 for crude and sex-related humor and language. Hell, that makes it sound bearable. Not so, people. Spade puts a soggy sock in the smart mouth he uses so deftly on Just Shoot Me and plays Joe Dirt as a mullet-haired softie searching for the parents who deserted him when he was eight years old. Joe even melts the heart of a radio shock-jock, played by Dennis Miller (seeing Dennis the menace melt isn’t pleasant). The heart of the film, in which Joe fights off a white-trash bruiser (Kid Rock in a kick-ass debut) for the love of a sweet thing (Brittany Daniel), is just an excuse for first-time feature director Dennie Gordon to heap cruel humiliations on Joe. They include having our boy attacked by a hungry gator and a cannibal serial killer. No pain, no gain. The cruelest stroke is wasting the great Christopher Walken as a mobster hiding out as a janitor. Walken helps, but he can’t deodorize a script (by Spade and Fred Wolf) that smells like uncollected garbage from Adam Sandler, who exec-produced this dead raccoon of a movie for former SNL buddy Spade. Some favor. In one scene, raw sewage is dumped on Joe. See Joe Dirt and you’ll know how that feels.