Shaving cream with food coloring mixed in to paint in the bathtub with. Not recommended for white grout! We rinsed it off quickly so we didn't have any staining. Fun, fun, fun activity - until he knocked it in the water - then we had meltdown!
I've been perusing quite a few "homeschool" blogs, and we have been trying some new stuff lately. On this day, we made a homemade pumpkin pie play-doh. Oh my, it smelled lovely, but was a little too oily for me. We'll be trying more in the future.