Pottery is perfect for a kid who likes getting messy, my nephew was the same. We took him to Pottery Studio 1, and they plan to run a
pottery workshop in Santa Monica for kids once the new studio opens, so worth keeping an eye on their schedule. Kids classes are $100 per child, two hours, and they take children from age three, so seven is totally fine. The instructor kept him busy the whole time, shaping, decorating, and he was very proud of his slightly crooked bowl. You can stay and watch, or even join in, my brother ended up making a mug next to him. The only thing, pickup comes a few weeks later after firing, so prepare him that he will not take it home the same day. My nephew asked every morning if his bowl was ready. Does your son prefer building or painting?