This was invented by me at the age of six or seven, when my mother started expecting me to do my share of the
dishes. I would hold my
thumb over the stream of water coming out of the
faucet so it came out as a thin
jet. I would then move the dish under the jet until all of the
caked on food leavings broke off and went down the
drain. The
dish could then be washed quickly, without
scrubbing, and without getting the
dishwater very dirty.
The downside was, of course, that water ended up all over the floor, walls, ceiling, and person doing the dishes. In the eyes of my six-year-old self this was more of a boon than a problem, but my mom saw otherwise :-)
The idea came from watching Cousteau's team of divers clean the mud and grime off of random undersea findings with a high-pressure jet of pumped water. What can I say, my family watched a lot of PBS.