Yep go with the bugs
I do the same as xdmray but I use a an iron cage and peg it to the ground. I'm lucky because i have a masive meat and colony in my back paddock that make short work of the left over nasty bits but DONT BOIL IT.
Boiling causes fat to soak into the bone, and makes it yellow and greasy.
Don't bleach them either, Bleach will make the bone brittle and chalky,eventually disintegrating the bone over time, no matter how well you rinse it. The best and easiest way is using bacteria to clean bones.
1. Remove as much tissue or hide from the bone as you can *enter the bugs*
2. Submerge the bone/skeleton/skull in a plastic bucket of water.
3. Leave the container in a warm location where you won't mind the smell. It's also wise to make a lid for the bucket out of window screen to keep mosquitoes out if you're keeping it in a garage or outside.
4. Periodically pour the greasy, smelly water out and replace with fresh water. If you have a garden, or a sad looking lawn, it's the best place, it really helps plant growth.
5. When the water runs clear, there's nothing left for the bacteria to eat, and you're ready to...
6. Soak the bone in regular drugstore strength hydrogen peroxide until it reaches the whiteness you prefer. The bones will be sterile after about 2 minutes, but you can leave them in there as long as you like. Don't use a metal bowl or bucket for this step, as you want to avoid weird chemical reactions, and rust getting on the bones.