I've used salt/heat with many sensitive fish including cories,otos,cardinals, and loaches with no losses. I used a dose of about 1 tblsp per 5 gal added over a few days. It's also important to remove the salt and lower the heat as slowly as you add it when the treatment is finished.
I have now changed to using Kordon rid-ich or the same fish as I could never get completely rid of the ich with the salt/heat, always seemed to re-occur just when I thought I'd licked it! Rid-ich is much easier, quicker,more effective, and I haven't had any side effects.