How water proof are horn and ivory?

I am thinking of either taking a horn tip or tusk tip (warthog) and setting a nib in it. How water proof are both materials? Can I just use them raw, or shoudl they be treated/sealed/finished?
Thanks!
Karl

I own some elephant ivory and a lot of warthog ivory and I think its safe to say that they are essentially the same. I figure that both horn and tusk were waterproof (because obviously they don't get ruined in nature) I just wanted to check.

yo might want to read this thread

elephants cool down in water, and buffalo are sometimes known as 'water buffalo.'

Both natural materials are subjected to water in nature and when polished for scale use are fully waterproof - ivory isnt even porous.

I have several razors in both materials and they are definately water proof - in which case I dry them anyway to prevent the blade getting wet through contact after use.