What electrical contact cleaner do you use and where do you get it?

[Gameguy]

I've used sandpaper before as well on connectors, works pretty well. For carts I'll use rubbing alcohol + art eraser + very fine steel wool (only if it's very stubborn). Don't like using steel wool too much though since it's essentially filing away the contacts over a long period of time.

Steel wool isn't that good to use, small fibers of it can get embedded in the metal that you're using it on and then it will rust. Bronze wool might be better if you need anything that abrasive. I know some bicycle collectors use bronze wool to remove rust from chrome parts instead of steel wool for the reason I mentioned. I wouldn't use anything that abrasive on games myself though.