Sorry, my post wasnt too clear. :sick:
What i meant was (in my experience on betta farms) if the fish is swimming on its side, especially after feeding, then its probably been a problem from its time in the bubblenest - (the raft that the fry begin their life). If the male does not tend the nest and the fry sink in their early life, sometimes the cannot swim properly.
From my experience, the fish is terminally ill in this situation.
BUT THAT IS ONLY IF YOUR FISH IS INFLICTED IN THIS WAY. I only meant to mention this as an 'option', because without the fish in your hands/sight, it is very difficult to make an accurate diagnosis! :thm:
Otherwise, try alternative treatment as rightly suggested by others. This is only a suggestion.
ALso, clove oil, in my opinion, is a homeopathic sedative, thats mechanisms are not well understood. Phenoxyethanol is the 'standard' (accepted by industry) method of achieving euthanasia for a fish that is termanilly ill and clearly suffering.