I'd personally go with salt first. If Ich Attack contains formalin, then don't attempt to even use salt with it. Salt and formalin don't mix. The combo produces lethal results resulting in the quick demise of your fish. Both along with high temperature can severely cut the oxygen supply of your fish rendering them incapable of breathing properly.
Get the med out with carbon and switch to salt. Continue salt treatment 10 days right after the last white spot was spotted. Instructions of how to dose is in my ich article in one of the sticky threads here entitled "Freshwater Disease Guide".
Whether your salt has iodine, it doesn't matter. Just watch out for yellow prussiate, the only anti caking agent that is dangerous to fish especially if exposed in sunlight generating a hydrogen cyanide substance that can intoxicate your fish. API aquarium salt is fine though.