Hmmmm....I believe freshwater dips do work on ich. Not sure about "recommended", but they do work as a deterrent.
Best suggestion would be to administer both a 15 minute freshwater dip before placing into your quarantine tank, followed by a 3-4 week quarantine period with no noticeable signs of disease before placing new fish into a main display tank.
MCary: I've performed a 3-4 day regimen of freshwater dips on my kole tang, which had saltwater ich, and the ich basically fell to the bottom of the freshwater bath. I had no medication in the freshwater, and I've read that the ich parasite cannot survive in water with little to no salinity. My clownfish also had black-spot disease, which I also treated successfully with a 5-7 day regimen of daily freshwater dips. IMO, they are effective...
Hope that helps, sruiz. Also, visit wetwebmedia.com for more tips and advice about introducing new fish. When I started out my saltwater tank, that's where I got most of my info.