Simmer in dish soap till clean. Change water when necessary.
Then use ammonia and soak for days even weeks for stubborn bones. You can use the fuel, and I have used acetone for super tough stains. I let them soak for a week or more, never had a problem with the bone integrity.
Then I rinse and let dry.
Then into 40volume peroxide for 6-12hrs. Then let dry in sun.
None of this is set in stone. A lot depends on my schedule and if I remember where I put them