The next solution I came up with was to maybe look at buying a Dog Throwing version which I know can chuck tennis balls and could be used with Slazenger Red Ball which have far less bounce and a lot more weight than a regular tennis ball. But this afternoon when I went over the Rec tennis courts for a bowl I took three of the Slazenger Red Balls and gave them a go and lo and behold they work and at £1.00 a go I reckon I can stretch to 12 of those for practice with Ben and Joe this spring. This also means that the Slidearm Pro despite being designed for full size balls seemingly is probably going to be okay with the youth size cricket balls as well.
Check out my other blog here - this is all about Leg-spin bowling and nothing else. Double click on the image below.