When I used it, I was on the ground floor with an outside door. We rinsed the
plaster mixing basins with a hose and washed up outside. I have inherited a
box of plastercraft. Now I am on the third floor of my school (great view of a
lake) but it all goes into a trap under the sink. I am concerned with rinsing
the plaster out in this sink as the water will eventually hit the pipes.