I use the recommended dosage when I first set up or when I have a loss or disease of any kind. But not when I do water changes. From what I've read, adding salt helps, but not keeping salt all the time.
I use it to clean often.
Recently I re-set up my eclipse hex 5 using old gravel, a piece of malaysian driftwood, and an old sponge filter. I added food and stress-zyme to cycle the tank. Bang! Fungus. Lots of it. I salted the hell out of the tank and changed the water a few times to get it out and now it's butters again.