I was scrolling through pinterest today and saw the best idea ever. I'm an adult and want to give this a go. The craft idea was mixing water beads and shaving cream. This would be an amazing activity to do with children, and a lot of us adult children as well.
When I was younger I worked in a daycare and one of our "fun table" ideas was to play in shaving cream, now put the water beads in and that would just be a blast!
This is such a simple thing to do too. All you need is water beads, shaving cream, and some utensils or some type of scoop. If you don't like a mess I'd suggest outside playing area, or some type of high sided tub where the shaving cream will not go all over. When my kids were growing up I just sprayed shaving cream on the table and played in it with them.