When I prep bones for art projects, I typically simmer them in a stock pot for an hour or two (don't boil). Boiling bones can cook the oils and fats into the bone matrix. It will give it a plastic looking appearance and leaves it slightly more flexible. I add soda ash and borax to the water if I'm not saving the "stock" pot liquid for hide glue. Removing the oils and fats via boiling will shorten dry time because oil evaporates pretty slow compared to water. I can't imagine this method wouldn't work for the preparation of knapping tools. I'm sure someone else will point it out quickly if I'm wrong.
The leftover water in the stockpot can be boiled down to make hide glue. That is if you're doing a potful of bones. Probably not worth the effort if we're only talking about two bones.
I contacted a venison processor recently. He gave me the okay to raid his scrap pile for ulna's, sinew, and bones if I want them.
