How to make good juggling balls homemade?

I used a tennis ball full of four, but my hot glue not very well keep it closed. (I ran out of super glue) Does anyone have any good ways to get them or any way you can keep the mines closed? Thanks

if you have the clay, use that. um … yes regular tennis balls are too light to juggle, I think. um … OH! Okay, take an old shirt or something and cut 2 rectangles. sew and fill with beans or something. or put rubber bands around tennis balls

Juggling Stein Tutorial – 4 Balls