Hey, thank you for the replies. I use sculpey gloss, with sculpey iii clay.
With holding the horn, I then have to set it down somewhere to dry too, which means it will have the smush of whatever surface I dry it against
Yesterday I attempted glazing it and I plonked it on some blu tack so I could access as much as possible with the first bit of varnish. This morning I woke up to an awful ring of dry gloss which I tried to gently sand away so I could do the final little bit, but you can still see the faint ring. :/