This sexual act requires 4 people: at least 1 guy and 1 girl; most preferably 3 guys and 1 girl due to the physical strength required. A Kellner
Washing Machine (KWM) is preformed by having one guy standing in a pool with his penis in the girl's pussy and she is curled up in a ball so that the 2 remaining people can spin her around and
back and forth, sloshing the water around as in an actual
washing machine. The girl may want some good goggles. Depending on the guy and the spin methods employed, the girl may also need a breathing apparatus.