they are called soap bars, soap houses or soap land. The rule is anything goes so long as there's no penetration.
as negus said, everything goes except penetration. its like you can chew on something but you cannot swallow...![]()
I never had the chance to try it when I was in Japan years ago. Pero nasubukan ko yung steam baths nila . . . muntik ng ma-hard boil ang badoodles ko!