I just use an old, stiff toothbrush and lots of water. You might also be able to find a flat, stiff brush at a cleaning supply store that would work even better. My mom had a great one from Fuller Brush. ... View related article.
If you really want frames, you can find a surprising selection at dollar stores. You just have to pick through them to find something tasteful. And don't expect them to last forever. ... View related article.
I would recommend The American Boy's Handy Book or The Dangerous Book for Boys (links below). They have lots of outdoorsy and other really interesting activities. Is he a Boy Scout? Get him working on those merit badges! Also you could think about volunteering somewhere with him. Help him to find ways to use his time productively, not just to pass the time. Help him to learn a new skill or hobby that he can show for his time. Good luck!