If you don’t do this already I recommend you start. I have my kids wash the paint dishes, cups, bowls, utensils, etc after they are done painting.
They not only love doing it. It teaches them responsibility and it is one less thing for me to have to do.
I just fill a tub usually a rubbermaid bin but in this case I used the water table with soapy water and sponges. I then dump in our paint containers (pie tins this time), and their painting utensils they used dinos, cars, and balls. So they scrub away make sure everything is sparkly and I have one less thing to clean.
Don’t want to have them clean dirty paint dishes? Have them “clean” your play dishes (non-breakable). They will love it and you don’t have to worry about dirty paint water.