This is why you may need to see someone trained in hypnotherapy first to learn self-hypnosis. The people you are talking about undergoing rituals such as
Thaipusam and
similar devotional ordeals are so focussed on becoming closer to the Divine that their "mind and body do not walk the same path" to quote a friend of mine. In this state the body produces it's own painkillers that are even more effective than morphine, that and the mental focus, are the basis for being able to do these devotional acts,
Some Western Witches do
use pain to reach altered states , but I'm not one of them(!) Indeed when I went to Japan to study Ninjutsu with the Grandmaster of the system I train in, some of my friends asked if I was going to do the traditional "Meditate under a waterfall in midwinter"
To which I replied "Yes- I've heard of several sites with nice warm thermal ones". Not the answer they were expecting apparently
