On a show last spring we had a bathtub on set. The production manager had a plumber in and we were able to control water flow both from stage and the booth. It was really cool. A character was killed by being drowned in the pool at the end of the play and the thrashing in the running water never ceased to surprise the patrons.
However, the tub was an antique and did not have a drain. This meant that at the end of the night I had to grab a hose, run it to a drain in the vomitoriums and run a siphon by sucking on the end of the hose. ICK.
Thankfully, after seeing me sucking back bathwater one night, arrangements were made for a small pump to be bought so that I wouldn't have to get a mouth ful of dirty water every night.