Just like the real thing, 777 washes off with plain ol' water. Pyrodex needs some careful cleaning, no matter what you hear. But ALL shooters of any of this stuff, real or subs, really need to get cleaning as soon as possible after shooting - on the spot is good if you can. The gun club to which I belong has loads of under-cover space to do this necessary chore.
My only downer with 777 is that it smells pretty odd - like a smell in a beet processing plant, and nothing like the mighty cow-fart of the real thing.
tac