If this fish is "covered" with white spots I don't think garlic will do the job. You need to get a hospital tank and treat all your fish in the hospital tank using hyposalinity.
FW dip, in and of itself, isn't going to cure ick or get the ick out of your main tank while there are still fish in it. The ick is in your tank, and will continue to be in your tank until you treat the fish [outside of the tank] leaving your tank wo fish for a month.
[ November 15, 2001: Message edited by: Beth ]