army shower
A quick shower that goes: water on to wet - water off during soap and shampoo - water on to rinse - done.
When soldiers in remote locations without adequate water supplies needed to shower, they'd run the water just long enough to get wet, then turn it off to soap their bodies and shampoo their hair. Then they'd turn the water back on to rinse. Hence "army shower". This phrase came from my dad, a Korean war vet.