Swimming pools glimmered with particular force in the yesteryear Hollywood sun. They were of great use to studio publicists, giving starlets a wholesome excuse to frolic half naked. They were rare and expensive — a genuinely dreamlike component of the American dream. In short, they were Rita Hayworthy. By the time Dustin Hoffman’s 1967 Graduate floated aimlessly in his parents’ backyard splasher, chlorine’s glamour had eroded right along with Tinseltown’s. Swell, then, that nostalgniks Evenhuis and Landau survive, intoning a kind of ”Where have you gone, Esther Williams?” in this fabulous homage, Hollywood Poolside. A-