I am sorry but I think intentionally breaking bones is bonkers, especially if the intention is giving yourself nerve damage. You could be paralyzed, you know!
http://www.handandwristclinic.com/article.asp?article=120
There is a practice among Muay Thai fighters to kick their shins into hard objects. This gives them microfractures, which thickens and hardens the bone. They are not breaking the bone completely, only slightly cracking the surface of it. The principle behind this is scientifically sound. Burning your finger only gives you scars. Scar tissue could make the skin harder and more difficult to tear, but it is a crap shoot. Edit: It appears I was wrong about this. Scar tissue is generally weaker than regular skin. Worst case scenario is that the fingers get useless, like two of Django Reinhards fingers, after he was in a fire. Odds are you won't get his musical talent, though.
I got attacked by a drug crazed maniac while out on the town some years ago. He was flailing wildly and you should have seen the look in his eyes! I felt that I was out of options and threw a combination, which while it did send him to the ground also snapped my middle finger on my right hand. It was a long 5 weeks, and a painful recovery, during which I could not play pool. Afterwards my touch did not get better, in fact it felt like I was playing with a thick glove on for some time. I don't recommend it.