The interior plumbing in the 1989 27' Bayliner that I bought this summer had been winterized last fall with non-toxic antifreeze. Hadn't been cleaned out when I bought it and about early July, I filled the water tank to check for leaks in the system. Had to take out the supply strainer to find a replacement, so I let the water (with diluted antifreeze)drain into the center bilge and pumped out what the pump would reach and left the rest. Three weeks later, I got the boat back from the shop where it had sat outside in extreme heat all closed up, and the smell of the remaining water in the center bilge was overpowering. Talk about going sour! Anyway, I sucked it out with the shop vac and dumped in bilge cleaner, and then sucked that out. After drying out and airing out for some time, the smell in the cabin is just about tolerable. Though dry, the center bilge area still has the faint sour odor of the antifreeze that I would like to get rid of. What should I use next, bleach diluted with water? Any one else exerience diluted antifreeze going extremely bad?