is there a cleaner out there to clean the copper brush hoods?

Get some train track cleaner and use a Q tip, you can clean the brush face and com with it also.

Wolfman

As Big Jim used to swear by..... Lysol All Purpose Cleaner and and soft bristle tooth brush.

TJ,

I used to use De-Oxit. It is a red electronic contact cleaner that removes oxidation and is also conductive - makes the copper shine. You can find it at Radio Shack but can be found in larger quantities for less online. Just clean through the hood with a Q-tip and leave it "wet".