During all the attemps dont use yourself to "entice" him to come out. Most ball pythons will acually inflate/hang on and try to hide more from a humane that is trying to get to them. You will make it harder for yourself. Using a live mouse sounds like the best idea to me. Make sure to stay away (but close enough to monitor) while the mouse is in there. If your snake is enjoying the hiding game then the shadow or sight of you may keep him from even coming out for the mouse unless a feeding is skipped. Good luck.