That's probably the prettiest underwear I've seen. Did you actually get him in the water? I'm always so curious about the BDJs and water. If I had a pool I'd throw my Obitsu's in it no problem, lol, but alas, I don't.
I didn't put him in the water, but mine have been splashed a bit. No harm.
A friend of mine has a Tan DZ Mo which fell into a lake once. She dove in after him and retrieved him and it appears that he has suffered no ill effects from the little swim at all.
I don't know the full effect that chlorine may have on a doll. I'm not about to test that.
If nothing else, getting the stringing in bjds wet could cause them to grow mold or rot. Chlorine in particular would cause it to become brittle. Of course you can always restring.
Regular water of course won't hurt the resin, but not sure about pool chemicals. Could bleach the doll.