I find that using my car key (long and not very toothy) is an effective method of scraping my bowl. I just scrape it along the side of the bowl much like when you're mixing brownie batter (not necessarily pot brownies) and you're trying to mix in all the shit stuck to the side of the mixing bowl. Same concept. Oh, and don't be afraid to use some elbow grease. Your key shouldn't be too dirty when you're done.