One of my trainers from thailand is staying with me for a couple of months and when he thinks hes putting on weight he stops drinking water because he thinks it makes him weigh more, he doesnt believe me when i tell him its temporary and you sweat it out. I hide in the laundry and drink water before training each morning because he doesnt understand that wetting my mouth wont keep me going for 1 1/2 hr sessions on the pads. But both my thai and local trainer dont like you washing the sweat off, and I sweat like a racehorse but they would rather hose the walls afterwards than let you towel or use water. It is supposed to be because it teaches your body to cool itself more effectively, in the early stages or when you are trying to push up a level you dont want to interfere with your body adapting to the situation, if you cool with water it stops your body from having to adapt to cool itself more effectivly. In theory when your body is working like a well oiled machine you can do what ever you like because your body can cool itself with or without help, so the ice and water during a fight just adds more pep.