Used them both. Its hard to tell exactly how much they helped with healing/ treating a problem but i'd say they dont hurt.
Some people treat them like the "magic bullet heal it all" - which i am very skeptical about. There undoubtly diseases that require a "real" medication like an antibiotic or strong anti fungal medication.
It appears though that melafix positively influences healing of little wounds or fins problems so in that case i'd use it.