Hi James,
I find it strange that you quoted from a site talkiing about freshwater ich. Marine Ich and freshwater ich are similar but Marine Ich has a longer reproduction cycle. You quoted the section relevant to you but you skip the treatment. The site recommends to use salt for treating freshwater ich which is similar to hyposalinity treatment for marine ich.
You said that the parasite will not leave the fish unless the fish has gone to heaven or semi dead but you also quoted from the website
So which is which? Does the Ich parasite only leaves the fish when the fish is dead or they will drop off after completing one part of their life cycle? Therefore if you see the white spot disappear after a few days, they ich is not gone but have went on to another stage of their life cycle.
Garlic treatment is not proven to work at all times and effective sometimes probably due to immunity from the fish.
Please read this thread for proven and effective treatment for Ich.
http://www.sgreefclub.com/forum/index.php?showtopic=37909