Cleaning Corroded Crossovers

I bought the Rockford Fosgate Fanatic Q Component system shortly after they were first released. The 6-1/2 Mid Range, Tweeter, and Crossover set.

The shop that I had install them put them inside the door panels. I removed them the other day so I could put them into a different vehicle and all of the gold plated speaker connections and several of the components on the circuit board are corroding. None of the corrosion appears to be something that would destroy the crossover but I would like to clean it and stop it from rusting further.

I have access to the full line of CRC electrical parts cleaners and other contact cleaners here where I work. These can be found at crcindustries.com and several state that they are safe for electronic boards and components. There are a lot of choices.

I don't want to screw any of the components up on the board. I'll need to use the nozzle to get down under the square ceramic block devices on the board to clean the point where they connect to the board because there's corrosion at those spots. Also the switch that says 0 or 180 is corroded about the worst of anything on the outside where it's painted black. On the back of the circuit board (I removed it from the plastic base) it appears to need cleaning where all the traces are it looks like a white film from moisture is there.

Can someone give me some suggestions on what I should use to clean, lubricate, and stop the corrosion?

Are there any components on the board that I need to be cautious of getting the cleaner into?

Thanks. (By the way I don't intend to reinstall them in the doors like the other screw heads did).

Just any spray clear varnish like Minwax from Home Depot?

Also, will it hurt to use a toothbrush and the cleaner to clean the back of the board where the traces are?

I took a second look and they are worse than I first thought. Some of the milky looking film is pretty thick looking in spots and even appears to be connecting the solder points but probably never actually shorted anything because it was all working fine when I removed them from the doors.

The right front speaker was distorting randomly and I thought I had blown it but it was weird because it wasn't a constant rattle it was only on certain songs (frequncies), so I am thinking that noise was a result of the corrision not letting the crossover work properly. Does that seem likely? I examined the speakers and they look like new.

Thanks

If I am correct the Fanatic Q series has been replaced by newer models and I can't find anyplace the crossover is sold separately. So, what would they replace them with? I can go back and ask for a replacement but unless I know what's equivalent I might get something inferior to what I already have. They came as a component set and that set is no longer offered so they won't have the crossovers that I have.

If I were to ask for a refund on the crossovers I wouldn't even know what the cost would be since they come as a set. Then if I did get the refund what would I buy to replace them?

Until now I have had excellent luck with this shop and I couldn't believe what I saw when I opened the door panels. I really feel I am better off just cleaning and sealing them, not using the shop anymore, and reinstalling everything in my new car myself.

However, if I do go back I would like to know what to expect when I ask for a replacement that no longer exists so I don't get screwed again and lose the crossovers that came with my component set.

Thanks