Would cause way too many implications, why let it be allowed if it's not for a "Role-Play" Advantage? It would only cause issues in sits where players could defend their actions by simply stating it was for fun and not for RP. This could easily be abused and the rules is fine as it is currently. Not to mention, I could imagine the amount of complaints about seeing random people flying through the air on bathtubs as it would be ruining players RP.