i usually bump the temp up to 85 and do 50% water changes for 3 days then 25% for the next 2 weeks. ick has approx a 4 week life cycle. im usually treating scaless fish as well so i dont use meds or salt. the water changes are key since the larvel stage is free floating once the cycst errupts.. so removing water is key to erradicating the parsites. also copper medications also only kill the parasite on its larval stages as well. if you cant do the water changes then the medication would be beneficial.
higher temps speed up the life cycle process which keeps the parasite in its cyst form minimally, so it speeds up to the point it can be killed.
copper/ high temps/ wat changes kill larva, or remove them. some strains are easy to kill with high temps alone, some need to be manually removed and/ or killed with toxins( copper)
ime non copper based ick meds dont work well if at all. keep in mind copper will kill invertibrates and can be lethal to scaless fish. also beware that with higher temps you will have less oxygen in your water as the molecules hold less, so keep your filter running. and your water movement consistant. the worst advise people get often when treating ick is to remove your media and/or turn off their filters.
and salt/meds can impact your biomedia.. so always do regular water testing while treating.