I have never had water in mine, but I have also never washed it. I wrap the whole thing in foil. Looks like new. I assume there is insulation inside, so water getting inside is probably going to have a negative effect on it's insulation properties if it is fiberglass. Maybe it is some kind of foam. It should be okay if it dries out, but it will be kind of hard to dry out. Probably just wrap in foil from now on, and maybe eventually the heat from usage will dry it out.