I had decent luck with the last one by burying it up to the antlers in the garden and then covering with a box. The underground bugs cleaned it up pretty good without damaging the small bones. I put in in a wooden box in the ground to catch any teeth that might fall out. Make sure you put a box over the top to keep mice and squirrels from chewing on the antlers.
Be sure and take mesures to prevent dogs from digging it up too
