Not everyone is a fan of the Bikram approach to yoga. Some call it macho; others call it a cult. But one thing's for sure: When you cram a bunch of mostly naked people into a studio heated to 105 degrees at 40 percent humidity, then guide them through a series of 26 postures over the course of 90 minutes — well, everyone will be a sweaty mess by the end of it. The key is finding an instructor who can keep you breathing steadily, even as your knees quake from exhaustion and your vision is obscured by a steady cascade of perspiration. At Bikram Yoga Castro — an adorable candlelit studio in Eureka Valley — LaMott Atkins oversees his classes with calm authority, calling out each posture in a maddeningly level voice as his students grunt and strain and attempt not to slide on puddles of their own sweat. It may not be traditional, but it's one hell of a detox.