This is not advise. This is just a description of how it went.
Two or three weeks ago, we took some cattle off to the vet to get some work done. In the corner, by the headgate, I spy some horns that have been removed from other "customers". "What do you do with those?", I tentatively ask (assuming it presumptious to even possibly cut into someone's horn supply, horn in so to speak). The vet almost acted like it didn't even register that anyone would want them. So they came home with us. Mind you, it's been hot around here and in a day or two these puppies really STUNK! So I put them in a bucket of water just to try to cover the smell and set them in the truck bed to put a little distance between them and the house. I got concerned after I remembered them a few days later, that maybe rotting in water may not be good for them. Well they stunk worse now. So they went across the pasture to dwell in a dry bucket off of the ground in the hay structure so the dogs wouldn't steal them. It's amazing how fast maggots populate something in this weather. No way these things were going to become something that I ever put to my mouth. Not knowing what else to do and having rediscovered them yet a few days later...the insides of the horns seemed loose and the dogs had such a pleading look in their eyes that I shook the inside plugs out of them and gave those to the very grateful dogs.
These things are actually sort of starting to look like something now that can be made into something. The insides were nice and smooth and after a short soak in water and Lysol to help with a lingering smell and I then settled on scraping them with a sharp knife to remove extraneous material, it was not unlike peeling a potato. I have now made a day horn out of one and intend for the other to be a priming horn.