Chinese martial arts has some training called "iron body" or a variation called "golden bell".
Part of the ritual is beating yourself with a "metal flogger" (for lack of better words) for 108 days, to desensitize nerves and increase bone density.
The metal flogger is a group of small metal wires straightened. The ones I've seen were about an inch in diameter and about 16 - 18 inches in length. Many are home made, but one of my buddies knew someone who had a machining shop and he made me a really nice one.
I'm hoping to know the name of this tool, so that I can do some googling to see if anyone sells these online. If you know the name that would be awesome. If you know some where online that sells them, that'd be even better.