Anyone the Wiser?

I have seen some unusual bathroom set-ups in my time. But this, on the Vietnam-Laos border at Lao Bao, has me completely stumped.

The ladies features one traditional WC, with door, fairly standard sink set-up, with mirror, and these two objects which I would, without making any risky assumptions as to their functionality, term bidets.

As you can see, they are positioned in cubicles, side by side, in a sociable fashion, so ladies can chat as ladies do. Yet the cubicles have no doors, and are only about waist-high (when standing) and not much higher when squatting.

The mop in the picture would suggest they are regularly used. But for what?

I hung around a bit, but no one came by. So I’m still none the wiser.

Answers on a postcard, please, to the usual address. In the interim, I’ll be going with “lustral basin”.