Actually, I see most of the problems with ivory knives coming from the knife *NOT* being used. Using and carrying an ivory knife really helps keeps it humidified (moisture from your sweat) and oiled (from your hands) and protects it over time. I've seen a lot of very old knives that have obviously been extensively used and carried with ivory handles that are in great shape. Rubbing a bit of mineral oil or orange oil or peanut oil into the ivory from time to time is a good idea too -- but letting it just lay up and dry to death is a bad idea.