Bodies of Evidence Gay advocates disagree about the dangers of bathhouses. by Steve Volk A tour of Club Body Center includes a trip downstairs, where David D'Amico hopes to create an orgy room out of a currently unused pool, and a stop in the laundry room, where high-tech computer-driven washers dispense just the right amount of detergent to keep sheets sanitary and costs low. "You find all kinds of things on these sheets," he says, lowering his voice. "Blood. Feces. It's all part of the business." D'Amico spends more time with the business now than ever. For years Philadelphia's last...