Clout is an excellent product to use for removing parasites on goldfish. IMHO, it wouldn't hurt to give both of your goldfish a treatment with it.
Goldfish are raised in cold water ponds and often have parasites that tropicals do not get. Since they live under scales and in their gills they are not always visible but they will drain the vitality from the fish. All too often, by the time they are noticed, it is too late to help the fish.