Glossy wrote:Мочало and мочалка could independently derive from мочить. Or мочалка could have originated as “little мочало”, which itself likely derives from мочить.
Yes, but what I was driving at is that it wasn't named that way because it is an implement for wetting, but because it was made by soaking lime tree bark. Modern мочалка isn't made this way, but it still resembles a bundle of fibers a bit. A big, soft, fluffy beard is sometimes called 'борода-мочалка'.
Nowadays мочалка is a rather specific washing tool. It is used more for scrubbing dirt than 'wetting' something.