Never been here, but it sounds like this place in Shanghai I went to. No running water, they had a piss bucket and a water bucket in the stall. About 20 stalls.
When the piss bucket was full or the water bucket was empty they called this kid about 10 and he took the bucket and emptied it in the toilet (or filled with water) in a nearby restaurant. BBBJ CIM, spit it into the piss bucket, then on to the next customer. The girls didn't even bother dressing between customers, just threw on a robe.
And yes you tipped the kid for dumping your pee.
And they say the wet markets are unsafe.