In a pinch I used to wash prints (11x14 and 16x20) by slapping them to the wall of my shower and aiming the head at them. Smaller ones were done hunched over the bathtub. (makes my back hurt even remembering those days.) I should point out that even though I had 10,000 sq. ft (75 yr old department store), money was tight so for a year I had a darkroom/bathroom/kitchen combo.