I doubt it really hurts that much. The hydrogen peroxide Mr.Vampire was talking about was where you take the fish out of water and rub hydrogen peroxide VERY carefully on the fish's tail, to get rid of the disease.
I only have 1 betta left, but he's a cool blue marble!
I put it in the same basket as docking dogs tails and ears etc... unless it is absolutely needed I would not do it. Need a cure... ask OFL for some advice. She will give the recipe for a garlic based, green tea, iodine infused, peroxide fermented soup that will have your betta feeling better in no time at all lol
(Disclaimer) the suggested remedy is in fact a joke and I do not suggest trying to brew this evil concoction... ask OFL for the real deal :)
Mourner of Rocky the BLUE EYED Pineapple Crowntail
Owner of Cory and Dora the Corydoras
Jimmy, Chopper and Harley the male Guppies
2 Cherry Shrimp
Planted with 3 Crypts and 8 small Java Fern (thanks for the clarification Abby).
aquaruim salt, and clean, warm water is ALL you need to treat fin rot, ime. :/ the ONLY time i'd EVER even THINK about cutting a betta's tail, is if it's a HM with SUPER FINNAGE, and he's literally having trouble swimming. :/ even then, i'd debate.