I have to apologize right now... I forgot which blog I found this idea on, I'm so very sorry!
But the good part is you can make some for yourself!
These were so easy to make that I did up a dozen while my sister was reading aloud
To Kill a Mockingbird which is an excellent book by the way.
(The next night I read to her while she was knitting)
All you need are some cellulose sponges of varying thickness (dollar store) and some zip ties.
Cut them into strips.
Divide them up.
Wrap a zip tie, pull it tight and snip off the tail.
We were 4 adults, in the lake having a blast throwing wet sponge wads at each other! And laughing our heads off! No, we didn't get beaned by the zip tie, you don't even know its there.