I have some sections of "Metal Jewelry Techniques", by Marcia
While the book does not mention antlers, it does cover horn and
bone working and polishing.
The data on horn seems not too hard on the material.
"To polish horn use powered pumice and water. After rubbing
vigorously, rinse and then polish further with a wet cloth and
powered coal. A final protective polish using soap and Paris
whiting will result in a fine, warm, soft, deep surface shine"
Chamberlain has the same Paris white as the final finish on bone
also, so it may be close. Maybe the place to start is with the
I once cleaned up some Hippo tusks with toothpaste. I get nervous