As a parent, there are times when you put your foot down and insist that your children follow your lead- for instance, teaching them to use a fork and spoon, not their hands. Other times,hand usage is a little more lenient. Like when your children start rubbing their bodies with paint, you could either stop them and repeatedly show them the correct method of brush on paper...or you could just let them at it and get the bath water ready. I did the later.
After all, its just washable paint. Not spaghetti sauce.