The vet finally got back from Mexico 8)
She says;
It looks like they already started treament. Basically a healthy fish should not get sores that lead to ulcers. There has to be some reason that the skin is becoming suseptable to infection like that. With the dwarf gourami we know that they have a virus that causes necrotic ulcers.
One of the things that causes a disruption of the skin and leaves it open to infection are ectoparasites. Lice and anchor worms are visible with the naked eye. Flukes are a little less obvious.
If you can rule out water quality, virus, and trauma I think parasites are really a possibility. Normal dewormers wont kill flukes. Praziquantal is what is reccomended. It is a relativly safe medication that is used in dogs/cats/livestock for the treatment of tape worms and people to cotrol tapeworms and schistosomas infections.
There are a lot of different reccomendations for treatment. It can be harmful to some marine fish but golfish usually handle it well. You can dissolve it in water and use it like a treatment bath, or you can feed it in medicated food.
Its also not a bad idea to increase the salinity of the water for a week or so. Or even treat the lesion topicly if your fish are large enough for safe handling
It sounds like your forum member has done her homework already and is off to a good start. I tried to join and post some confirmatory info but I couldnt join so you can pass along what you want from this