You might have to take a Provider to the Sybaris or Prestige Club for a Hot Tub / Bath Session.

A wonderful way to go about it is to request someone with either a nice apartment incall or a suite option.

A lot of hotels have showers nowadays; however, some have baths. I had a fantastic suite in the loop not too long ago where, seriously, the bath was like a pool. You could fit 5 hot girls in there. (Imagine that lol.)

I invited a guy over to come greet me in the am while I was 'bathing' and it was hot (literally and theoretically lol.) Very fun, and a nice way to wake up, IMO.

Other than that, bath tubs are usually super small.