Brand new Rainbow High Bathtub in purple, can fit Barbie as well. It’s missing a connector to attach the shower head but I’m sure it can be rigged with something else and be just as good.
It has two clear shower walls and a button pump at the back, I’ve never tried it but the tub has a drain hole.  The shower head has four little holes as well.  Curiouser and curiouser.
If anything it is just as cool to be in a dollhouse and for imaginative play.  Pieces separate easily and snap on for assembly.  Very quick to put together.