Riley, Yeah, you are kind of describing the nature of the beast. Sometimes they will get all ugly and nasty and such like that.
Unless the horn is off a young cow, there should be a lot of thickness to it. Should be able to be scraped, sanded, buffed back to wonderful. Then, as was said, put a nice coat of hard paste wax on it or buff on a wheel with a white compound (about 600 grit).
I made my bison horn about 26 - 27 years ago, and it is still looking as good as the day I made it.
Hope that helps.
John