That MAXIMUM of pain given to the guys’ balls would be by a CATTLEPROD or a TASER, and as he’s waiting to the moment his balls will explode…. the MAXIMUM pain should be given to them, my opinion!
Besides, the prodding can be done multiple times, so the exploding of the balls would be suspended, increasing the joy by the cattleprod-holder, making the expectations of the guy for his balls to explode would increase also……..