Leslie Easterbrook (of the POLICE ACADEMY series) plays the sadistic supervisor of a corrupt insane asylum in MANIACTS (2001).
Knull's favorite "correction" for troublesome inmates is the Hydro-Therapy room. She straddles a fire hose and "cools off" a girl.
Later, the girl punches out the big blonde and hauls her to the Hydro room to return the favor.
Before leaving, the girl turns up the water pressure to MAX and locks Knull in the room where the fire hose whips around crazily with so much force it blows the tiles off the wall. The water jet finally finds the evil woman and blows her to a bloody (and much deserved) demise.