My normal bp is over 700 grams and is less than a year old. He eats every 7 days. He gets a small rat, and sometimes an additional adult mouse if one of the others does not eat. He passes waste about every 3 weeks or so. Guaranteed to go like clockwork when he sheds.
Let him soak for about a half hour or so in some warm (not hot) water. It may take a couple of soaks to work. Also if you handle him after the soak he may go for you (or on you) LOL. Exercise always seems to help them go in my experience. I think the biggest problem is that he is not fed often enough or enough food. Try a small rat every 7 days, or a couple of adult mice. Good luck!