You have to ask yourself how the twist got in. It probably didn't happen in the bath It probably did happen in or around room temperature. There really isn't any reason to believe it needs something other than what got it twisted to get it twisted back.

If you are just talking about the water as a heating medium, with zerro penetration of moisture into the wood, then that certainly isn't a huge risk Arthur. But it then becomes a question of just what the heck the warm water is doing. To plasticize the wood, the glue, or the pultruded glass requires considerable heat, warm water would be all but useless. But as long as it's working why worry.