How about a Buddha board. It’s essentially an art board that you draw on with water. When the water evaporates it’s wiped blank and can be used again. Basically mess free and an easy arts and craft https://www.amazon.com/Buddha-Board-Mini-2-Inch-Black/dp/B000LUYQ22?ref_=ast_sto_dp
This isn't what you're looking for, but I have one of these and it's really nice. It's called the Buddha Board. It's a canvas that you paint on with water and the water dries up in like 30 seconds or something. The idea is based on living in the moment and letting go I think.
They sell bigger ones too.
buddha boards are pretty relaxing. got ours at NOMA. my kids love it, periodically. Could not figure out how to search NOMA's shop online, so here's the amazon link. Much less messy than sand! :)