"He washes the dishes."
Translation:הוא שוטף את הכלים.
In both examples רוחצת is understood, but I would use שוטפת. I can't think of any situation in which I would use רוחצת. But some people - and again, I don't know if it's an age group or a linguistic community or just specific people that I know - make a distinction between just running water over something, and scrubbing something clean. I believe the former is שוטפת and the latter is רוחצת. I hope other native speakers would comment on that so we can compare notes because I'm not sure.