Brain Fart for those who don't have washing machine onboard

When I used to camp at a lake in Oklahoma they had a 55 gallon drum with a clamp lid. There was a series of holes drilled in the barrel with a wire bridle you could tie a ski rope to. Every few days everyone would toss there dirty clothes in the barrel a box of soap was added the drum loaded into a boat
Once in the middle of the lake the drum was tossed overboard and towed around for about 15 minutes.