I can vouch for what Stanton said.

I degreased and cleaned the regulators in my A12 on the cheap. Even got away without having to paint.

Whats needed:

1 can of cheap $1 store oven cleaner (depending on grease build up)
Meangreen spray leaner for the $1 store. (wesley tire cleaner also works awesome)
A few sink/kitchen brushes from the same store.
1 gallon of Evaporust
1 storage container (like the clear ones you use to store clothing in) $5 at the $1 store.

I degreased with the meancleaner and brush a couple of times, washed down. Then mixed some ER with some water and soaked for 30 or so minutes. Checking often to not remove any factory coatings. Scrubbed a little with a plastic kitchen brush. Rinsed, and sprayed with a rust preservitive. I used some products for Shafco called Rust Veto.