Garlic for whitespot!!!
There are guys believing in garlic.
At least it will help your to entice your fish to eat. As long as they are still eating you can get them through whatever. But when they stop eating, then the battle is as good as lost mostly.
Its like humans, who when we feel sick are not too much in the mood for food. But let somebody walk into the room with a freshly made pizza, with a little extra dash of garlic. Yeah, you will ask for a slice.
Up to now, I never used it. I see it as not a cure, but a tool to help you keep the fish on eating. In that regard it should also help out in all other bacterial infections as well.