I found this cute summertime project on The Crafty Crow. They are called 'sponge balls' and are super simple and fun to make! To save $$$, get your sponges at the dollar store!
To start, cut you sponges in thirds lengthwise:
Tie a bundle of nine sponge sticks together with heavy string. We happened to have some nylon ties and I figured that would be pretty sturdy, so that's what we used:
Pull tight to secure:
Dunk the sponges in a bucket of water and let the kids pummel each other to the death!