I had a very experienced diver tell me that they put about 1/2 cup of vinegar and 2 cups of water in their bc, air it up all the way, shake it around and let it sit for a day. They then shake it up every day for the next copule of days to "re-coat" the inside. They said they usually just leave the solution in the BC until the next trip, but sometimes will rinse it out after a few days. One of his BCs is VERY old, and has the original bladder, so this can't be too bad for the BC.... any thoughts?