First thing if your set up is correct then you shouldn't need the bath. If you maintain a proper humidity level within the cage then the most you will need to do is possibly mist him a couple of times prior to his shedding. And you must understand another thing and that is what worked for your Ball will not work for the burm. Can you even imagine the difficulty in trying to move a 100 pound snake and try to give it a bath especially if it doesn't want one. You need to fully understand what it is you have gotten yourself into.
As far as the snake eating while it is blue, it is highly unlikely that it will. I wouldn't even try offering it food unitl after the shed is complete. And like what was already posted ensure that the snake sheds its eyecaps. Hope this helps, Todd