[Axis29]

Amber shelac.
I've heard tea works, coffee would probably work faster. But I would think they would just wipe off too? Plastic not being porous, ya know.
Some klinda oil... like used motor oil would work, but your guitar would always smell like a garage. Although I'd be afraid that the oil or some additive might destroy the plastic some. Again, Dunno....


These are just guesses. I don't have any first hand experience with a method that actually works. Other than having it around for along time. But my only old pickguard is black, so you can't tell anyway!?!?!?!