It's called a "Wonder Wash" http://www.laundry-alternative.com/washing.htm
We thought we'd give this a try for those days when we just can't be bothered to jump in the dinghy and find a laundromat.
Our first try was two pairs of Mark's jeans. Following the instructions we added about 12 cups of water and 2 tablespoons of detergent.
An airtight lid gets screwed on the top. Supposedly this increases the air pressure inside (when using warm/hot water), which in turn helps force the detergent into the fabric.
Admittedly, not very exciting, but considering the highlight of our last post was our new "Pooh-Meter", things are looking up!