DS wears cloth training pants at night. He stays dry about 50% of the time. A few weeks ago when we went to the zoo, he came home with a rash right along the elastic lines of his underwear. It was a warm day, so I thought it was a heat rash. But then it happened several more times and I came to think it was from the wet training pants. We went without them for a few nights and the rash cleared up. During that time I did a boiling water/Oxyclean treatment on them and followed up with a regular wash with Charlie's Soap like I always do.

He never poops in them so I hadn't been doing any kind of sanitizing treatment on them, but I'm wondering if I should repeat the boiling water/Oxyclean (or some other process) regularly. Does urine get trapped in the fabric or something? Can it burn skin like that?

We didn't cloth diaper so this is all new to me.