I bought a little mare last year. She had them. When I saw her the first time some months before, she had them and so did her pasture mates. The owner said "oh they will go away on their own, it takes about six weeks". Not in hee case it didn't nor her pasture mates as I picked her up 2 -3 months after I first saw her and she still had them. Poor little thing had a LOT of them too! I then brought her home, isolated her, and called my vet who told me about the wart/mix/shot stuff. I did not use it, but when my equine dentist was here he simply took his surgical scissors out and snipped a couple of them off. They were all gone is a couple of weeks then.
I have asked some trainers too what they do about them, and they tell me the same thing. They snip them off with scissors or pinch/pull with their fingernails.
B