Originally Posted by Geek
I wish I could get my overflow bottle that clean. Mine had gotten quite a bit of crud in it and when I disassembled the rads, etc to flush it last fall I tried all kinds of different things to get the slime off the inside of the bottle to no avail
Geek, you've probably already tried it but some stuff called Simple Green
seems to take dirt and stains off bike plastics amazingly well if you let it soak for awhile. Has worked well for me in the past getting ground-in dirt out of white sidepanels.