Never been a fan of Melafix. Get a Q-tip, dab it with betadine and carefully swab the wound with it. Then add a teaspoon of salt per gallon in your tank. Add another set in the next 12 hours totaling 2 teaspoons per gallon. The whole purpose of salt is prevent bacteria from latching on the wounds while the iodine solution (betadine) allows it to heal properly. Be sure to aerate water as well since salt depletes oxygen supply. Treat separately.
Lastly, make sure your salt has NO yellow prussiate added. Iodine content however is not an issue so don't worry if you use iodized table salt.