Originally Posted by alaxfire

I have more than once run mine with the MAF disconnected, as I had to disconnect it to remove my E320 engine cover, and forgot to hook it back up.
Use some very fine emory cloth, or an actual contact cleaner tool ( made for cleaning relays ) - you can pick one of those up at any electronics supply. There is also some 'contact spray' cleaner you can try.

If it comes to it, you can make a pencil eraser pointy and use that, just make sure you remove the left over rubber.