When we camp we carry a five-gallon bucket with a lid. We put in a little soap and warm water, dump in the clothes and let them soak overnight. Better yet, we put the bucket in the back of the truck and let everything slosh around while we drive to our next destination. When we arrive, we rinse the clothes, ring them out and hang them to dry. This wouldn't work well for big, heavy garments, but for socks, T-shirts and undies and the occasional pair of shorts it is a great, lazy way to do laundry. And it doesn't use that much water.