The best way is the longest and most painful to prolong the hanging. Hooks will rip through the ball sack, so best avoided.
Tied at the base of the balls allows maximum stretching of the sack, and pressure on the balls. The male will scream with a high pitch at this. Use rope or thick cord.
Something thin like wire will sever the man from his balls quickly, and ruin the enjoyment of the audience.
To prolong it even more just hang him for 15 minutes, then 15 minutes rest, and so on until he expires or you get bored.
