This depends on the salt amounts in the water... If your fish is sick the salt baths help him... Also what do you mean by constant?
Let me also put this in prospective... If you are getting a serious heart surgery you'd have to be put under anesthesia no questions asked... BUT, lets say you had to get a small finger surgery for a splinter that went fairly deep... You would only need a numbing shot to cope.
Basically your fish isnt on deaths bed and doesnt need some harsh medication, it just needs some light salt.