To the salt water post:
The theory behind hand hardening was deveeloped from breaking (ie bareknuckle board breaking) and usualy involves three steps that each have a very specific purpose.
The first in impact, to build your joints and bone structure, this is what you are doing everytime you hit the heavy bag, and why after time what once was a strenous session on your hands now leaves them unmarked.
The second is skin thickness/toughness, which is where the salt comes in. Drying out your outer layers creates thicker skin as the inner layers build back up, same effect as someone who has "leathery" skin from sun burns.
The third is nerves, which is where the hot water comes in, this normaly involves soaking your hands for set periops of time in the hottest water you can handle. Your body will actualy send messages of pain to your mind from heat far before any damage is done as a warning (which is why if you leave them and do not move them, the pain will go away). By raising the pain level/removing the early pain warning, you will be able to push your hands much harder without the constant dull ache.
Here is another hand related question, I fractured a knuckle some time ago, but did not realize it until months afterwards. It does not stop me from hitting the bag, but if I am going with just wraps it is a distraction. Any advice on what to do? I would hate for it to start to interfere. I have already been told to watch it carefully, and the idea of icing it before comp. has crossed my mind.