How do you treat ich with salt if you have scaleless fish in the tank?

One of my 2 clown loaches has ich and I would imagine the rest of my fish may be soon to get the same. In the tank I also have 2 irredescents, 2 balas, and 2 rubberlip plecos. Is it possible to treat ich with salt, having catfish in the tank? Some meds say "not suitable for scaleless fish" does that mean it will kill mine or simply be ineffective in treating them. Water properties are very good and I keep the temp at 80deg C. Everything seemed fine in the tank unitl I put the loaches in and they're the only ones showing signs of the parasite.