If you are using Hikari Ich X then I checked their website and tried their product safety sheets. All I got was a Hikari website with a bunch of adverts on it.
The Hikari Ich X contains formaldehyde (a preservative), methanol (a type of alcohol), and Malachite Green.
Malachite green is carcinogenic so avoid getting it on your skin and wash your hands with warm soapy water after handling the medication or working in the tank.
Methanol is pretty toxic too but is diluted into the water and should not be an issue.
Formaldehyde is a preservative that you should avoid contact with. It is regularly used to pickle/ preserve animals in science labs. You should not get it on your skin. If you do get it on your skin, wash it off with warm soapy water immediately.
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Malachite Green treats protozoan infections like white spot, costia, chilodonella, trichodina and velvet.
Formaldehyde is regularly used in fish medications to help preserve the medication and stop it going off, but it also kills a lot of microscopic organisms that harm fish.
Methanol is used in some medications to make other chemicals more soluble in water.
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I would stop using salt and finish the Ich X treatment. Just follow the directions like you have been doing. You need to continue treatment for at least 4 days after all the white dots have disappeared from the fish.
After the treatment you can do a few big water changes and then look for Praziquantel to treat the fish for gill flukes. Praziquantel is much safer for fish has the added benefit of treating tapeworm and gill flukes.
If you plan on getting more fish, then don't treat the tank with Praziquantel until you have the new fish. That way you can treat all the fish at the same time. If you have a quarantine tank, then you can treat your main display tank after the Ich X, and treat any new fish for worms and gill flukes when they are in the quarantine tank.