It isn't an actual plunger, but it sounds like it breaths with every up and down motion and really forces the water and detergent through your clothes so they get really clean. Search Google for "hand washing machine." If you live in an apartment or just want to use it when you have a few items, it can help save on time and money, and water.
I had to wash my clothes by hand for a month once when I moved to a place with no washer/dryer and I had no money for the laundromat. Luckily, I had a clothesline, but they still didn't really feel or look right. Plus, hanging them up wet stretched out some of my cotton shirts and they never regained their shape.
Wow Kami, that must have been a tough month. So many of us take a washer and dryer for granted. Hope things are better for you now.
I thought you were going to talk about an invention. Most people today are just too used to their appliances.
