M.P.
C., my husband swears by a product called Triple Antibiotic Ointment made by The Wellness Company. If he uses it when he first feels the beginning of the fissure, it immediately reverses and never forms. So I would say, he uses it a couple of times and it's gone.
It is a wholesale store, but you do NOT have to buy in bulk. The cost is very economical, about $5. I don't sell this, but I can direct you to the store as it is membership only.
I know it is really painful because I know what he went through in the past.
Good luck.