Wall plate connections w/ speaker wire

[zepman1]

I am planning on running some in-wall speaker wiring to wall plates. Wall plates will have gold-plated terminals, and will be using gold plated banana plugs on the room side.

I'll probably just make a bare wire or spade connection to the back of the wall plates. I am a little concerned about oxidation on the wall side connection. Is there an effective way of "sealing" the backside connection to avoid oxidation? I will be using standard 12 ga. Belden wire.