1 box of cornstarch
1-1/2 to 2 cups of water
Add water to the cornstarch until it is semi-firm. Sore covered in the refrigerator. As it becomes dry from storage or handling, add more water.
This cleans up easily. If it gets on the floor or carpeting, wait for it to dry. Sweep or vacuum up. If it gets on clothing it comes out with water.