I love the martial arts choreography in movies like Crouching Tiger Hidden Dragon. I asked a black belt friend how he hardened his hands for real (not staged) competition. It seemed simple enough. Set up a five-gallon bucket of white rice and punch your hands in it 10-12 times in a row five times a day. When that no longer hurts use a five-gallon bucket of dry beans for several weeks and then graduate to five gallons of sand.  While it takes time to become hardened it is a simple process. My martial arts friend cautioned me “Be careful. The process is irreversible once the calluses are there….and you could…