I'm gonna have to agree with everyone. THC is an aromatic terpenoid is not very soluble in water. THC is best soluble in organic compounds especially lipids which is why when you make brownies you use butter. Scientifically i would say this makes no sense what-so-ever. Plus i have boxed plenty of bathrooms and i have never experienced such a thing when i take a shower the next day.
even if this could remotely work - you are basically trapping a cloud of smoke in your shower for what 24 hours? then going back in to get high off it? it would be stale as shit, at best. and like someone said, your mom or dad is gonna go smelling your hotboxed shower and get pissed.