The State of Bones
Raw bones = good
Cooked bones = bad
What about bones from cooked chunks (such as from cooked chicken leg quarters) when most meat has been cut off. Then cooked bones put through a meat grinder to make very tiny pieces? Put through a sifter of some sort to make sure no larger pieces get by? Can these then be used to add to ground MM? Considered a type of homemade semi-bonemeal?
I don't see where these would be a danger due to size. Also, the meat would not have had any additional seasonings such as salt added during cooking.