A pair of microfiber trunks. Soft, thin, and quick dry.
The black thing hanging on the left is a plastic sheet that I lay over the sink when a large drain plug is missing or leaks, which is most of the time.
Or I stick a piece of duct tape over a small drain hole. I let it soak for a half an hour in hot water so the detergent (from the green 10B packets from 7-11) has time to kill the stinky bacteria. Let the soap do the work while I relax.