Garlic

So.... I got a coral beauty angel fish about two weeks ago (different place than I got the tang). Was doing good but noticed it really wasn't eating all that much and I was giving him a variety of things which the rest of the tank loves....(2 Fire fish, 1 cardnal, SF eel, brittle star,, CUC). A few days ago I notice white dots which quickly spread to cover its body. So I start doing some research and I find the one remedy that I don't hear to much about is garlic extract.

I had never heard of this to ich but apparently it is fairy common and one of the only ways to do it..... So I drove to the lfs I bought the fish from and sure enough they have it..... And they tell me that they use it for all their feedings of tangs and Angels because that is the only way they will eat.... Kinda pissed me off.... Someone should have mentioned that when I asked "what have you been feeding it".. So I left and drove to Petco and sure enough try have the same practice.... So I buy someone add it to next feeding and wala Angel eats a ton for
first time since I bought him. So three questions....

1. Is using garlic a "thing" for lfs stores to help keep the fish distressed in a small environment?

2. Will the fish always need garlic to eat?

3. Has anyone else used it to cure an angel of ich?