Stuff my vet warned me to stay away from with same (similar, at least) symptoms:
Get rid of the wire brush. The metal on the ends sometimes pokes into 'em and starts the reaction, and if you never change or get rid of the brush, same thing.
Coal tar shampoo. You don't need to use it daily. Do it once, wait a week, week and a half, do it again....if needed, a third time about a week, week and a half later. We never got to the third time before it was flat gone.
Fish oil. We were told to just get some sardines and chop one up and feed it to the cat with its regular food. I bet your idea is way cheaper.
The only reason I started with the coal tar shampoo is it was easier, and I hated the idea of having to medicate my cat daily for the rest of its life. If the coal tar didn't work, I had no problems doing it though. Seeing the ease of your method, I may do it for a treat for 'em.
My cats brush themselves, they love ANY brush that much, that they'll hold it and brush themselves silly with it. The wire brush would end up drawing little pinpricks of blood all over, they'd work that thing over so bad!