We play a ton of games using sponges instead of water balloons because they are easy to set up, hurt less, and easier to pick up as well as better for the environment. The way we have gotten the huge number of sponges we have been using has been to buy Grout Sponges in bulk from places like Home Depot or online. Then cut them in to 8th’s using scissors or a chop saw. Chop saw is much faster and creates some funny saw dust. Scissors leave you with a sore hand but works just fine. Joe Richards at Pierce Williams encouraged us to cut up old mattresses which is what we will be trying this summer.