At least one person has claimed that jow is an important part of IP conditioning. He also claimed that the improper use of it was responsible for making his bones brittle by leaching the calcium from the bones.

This brings up a question:

There are already scientifically proven methods for hardening and increasing bone density. Simply hitting harder and harder surfaces or lifting heavier and heavier weights in a progressive manner has been shown conclusively to increase bone density.

Why would one want to use a substance that has no scientific evidence of working, while at the same time, potentially weakening the very structure one is trying to harden? Why not simply go with the proven method without adding in the potentially dangerous, unproven method?