Preferably preformed in a warmer environment to allow the balls to droop to a sufficient level, a female (or male) based off preference. Will then preform a speed bag technique commonly preformed in boxing to said nuts.
When your female partner has an enlarged hemorrhoid and at the time of performing oral sex just before climax you slide your tongue down and bop the said hemorrhoid back and forth to mimic a boxing speedbag.
Bro i speedbaged my girl last night and she twitched like she had 1.21 gigawatts runnin 88 mph through her fart biscuit. Speedbagging at its finest