I made 'kinetic' sand and it turned out great. Sift 10 cups of play sand ($3.50 for a 50 lb bag at Home Depot). Add 5 cups (about a 1 lb box) of corn starch of a store brand which is under $2.00. Mix well, then add 1 cup of water, or a little more until you get the right consistency to make it stick together without being wet. Keep in a sealed box. If it dries out, simply add water. If you add enough to make it like mortar, you can make a sand bundt cake that can even be carefully sliced!