Separated from regular society if you talk about those desires and engage in fantasies and the like. Something little better than a jail. If they swore off their desires and quit behaving like a person who wants to molest children then maybe after 10 or 12 years they could have a 3 year probationary period to see if they could live in polite society. But for the ones who commit any crimes at all use those incidents to give them long uncomfortable prison sentences and swiftly carried out death sentences for rape or repeat offenders. Sure, hang them. That's the last way I would want to be executed.