This got taken a stage further when some psychotics found that if you pulled a long piece of stiff wire hard and fast in a to and fro motion against a desk leg, friction would make the wire very hot. Very hot.
The fun was then to apply this home made branding iron to someone elses' flesh while it was still at max heat. The victim would have to show ultra-bottle by not flinching, screaming, or retching at the crematorium smells emerging from his cauterised arm.
There was interplay on the basis of how hot the victim thought the torturer could get the wire, how brutal he could be, and finally that it would then be time to reverse roles. So at first it could be quite experimental and gentle, no more than red marks or the odd blister. But then it got vicious.
It went wrong when the manky infected wounds were noticed, and a general inspection of the boys' limbs was held. The fact we all looked like deflated Michelin Men was noted, and we were all roundly bollocked.