Thanks very much for clarifying!
I "enjoy" being on the receiving end (unfortunately never with you, MayaMidnight, yet), and you describe exactly the experience I have had!

What I like to add:
Tying up balls (not that you have suggested it) for ball-busting is probably not a good idea. Yes, if the ball-sack is pumped up like a balloon, the testicles themselves are somewhat protected from impact, but the risk of injuries is much higher! (I like maximum pain with minimum risk of injury!)
With ball-kicking the way you describe it, I never had an injury to the balls or testicles.
But I had hematoma due to impact with light objects such as a riding crop!