Cheers Ronnie, I've seen them and they are too small why pay for them they won't work when you can get tennis ball bigger and does the job !!!
I tie a knot in the hose right next to the connector. Why buy a tennis ball, a ping pong ball, this ball or that ball and what ever ball and all that stuff and drill holes?When the bit of hose wears out after a 6 months or so, I cut 4 inches off and tie another knot.