Put the clamps on your nipples horizontally, so that the handles of the clamps are either side of your nipple. Leave for 3 minutes. After 3 minutes take the clamps off, rotate 90 degrees (so the handles are now above and below your nipples) and put them back on.
Do this as many times as you can handle it. Now take that number, and minus it from 10, so if you managed to rotate the clamps 6 times your number is now 4 (One rotation is taking them off, rotating, putting them back)
You must now wait that many minutes with the clamps off. No masturbating though you may watch porn. After those minutes end put the clamps back on in any direction and you now have that many minutes again (with the clamps on) to cum.
Failure to orgasm means you must rotate the clamps and try again until you either cum or give up. If you give up then you may not cum for 12 hours.