Letting the water run across your fingers for a second or two before leaving the rest room is not handwashing. Rubbing your hands together under running water is not handwashing. Thinking about washing your hands after leaving the rest room is not handwashing.
The following is handwashing, as explained by registered nurse Diane Hays:
1. Use the warmest water you can, since dirt is dissolved better at higher temperatures. Use running water, whenever possible, not water standing in a basin.
2. Leave rings on fingers. Their crevices may hide some bacteria, but you will put them on after you wash anyway, so best to give them a token bath.
3. Lather up with the soap of your choice. The liquid soaps in a pump container have the advantage of not leaving residual goop, in which bacteria can grow. (Some bacteria can thrive on a bar of soap.)
4. Wash one hand with the other, then scrub each finger individually with the other hand. A fingernail brush is nice, but awkward to carry around. Instead, use the "grip scrub," where you cup the fingers of one hand into the cupped fingers of the other and massage them together, cleaning the nails against the looser skin on the inside of the knuckles.
5. Scrub for 30 seconds, rinse thoroughly, dry well and, if desired, apply the hand cream of your choice. One is as good as the next, the professionals say.