Well, in the place I frequent it means you can have a shared jacuzzi type bath with the girl, before or after the fun.
In another place I know they do have a sauna ie a hot and steamy room - but they ARE a massage place with just a bit of HE from some
What it means on most of the profiles I cannot think. I know it is on the profiles of some who simply have a small flat rented by the week and there are damn all such facilities in there. Just wishful thinking I suspect