OK you are all wrong sorry to say, you are supposed to lower salinity, reffered to as HYPOsalinity, not HYPERsalinity.
The only posts that make sence are the freash water dips as they cause osmotic shock with litteraly bursts the ich parasite, but you cannot osmotic shock your tank, so you need to quarentine all your fish for 5 weeks outside the system wile the parasite lives through its cycle and all dies out, if you cant do that you need to do many massive water changes, and even that mite not help.
Here is a link its good, its thurough and its not posted by a bunch of people who contradict themselves and know nothing about the biology of the parasite. This is a completely non-medicated method, and will not harm fish.
http://www.chucksaddiction.com/ich.html