I've cleaned lots of fish scales... just some newspaper and a smaller hunting knife (110 works well.). Don't really like them, but cleaning them is a problem - but must be done. I guess maybe a 120 and a LOT of newspaper for buffalo scales, just never knew they had them!
Seriously, horn is like hair - it's hygroscopic - sucks up/loses moisture content with humidity changes, causing it to grow/shrink like wood. Sealing one side - and not the other - will cause it to warp. Not sealing the ends will cause the length to shrink as it loses moisture content. If you sealed it all over, it would look more like plastic. Lose-lose, I guess. It is pretty, though.
Stabilized, like some burl woods, might be a choice. Turning raw wood is fun - but it is a large-scale version of the shrinkage/warpage problem, often remedied by submerging it in PEG1000, a polyethylene-glycol mixture, no, not 'Prestone II', that actually displaces cellular water. Has anyone tried that? It may not even take epoxy as an adhesive afterwards - and takes time.
Stainz