I lent an amp and a bass to a friend and I just got them back today. They are both covered in a yellow slime from cigarette smoke, and they stink so bad I don't want to bring them into the house. I can deal with cleaning the bass, but how do I get that small out of the amp? My guess is the speaker cones are permeated with the stuff, and the front speaker cover is going to have to come off so I can get to the front of the speakers. What can I use to get the smell out of the speaker cones?