Usually works like a charm but I’ve been doing that for 9 days now and nothing. Even with salt and meds.The best and easiest cure for ich is heat.
Raise the temp to 30 degrees with no meds. The lifecycle of the ich parasite is sped up by the heat, so they will drop off of the fish quicker at the higher temperature.
regular gravel vacuuming and water changes will help to reduce the free swimming parasites.
this was the advice given to me, my ich went and I lost zero fish.