I was giving mine a full respray which ain't all that difficult and my first step was to remove stubborn dirt with a Brillo pad.
To my suprise this didn't remove paint or dull the colour, it actually cleaned them up fantastically.
The only thing is I could have just been lucky and rubbed with the right pressure and amount of water.
I don't advise doing this unless you're willing to paint them afterwards should it not work out!
But if you were the Brillo pad definitely worked for me and had I not already got the gear for painting I would have left them with just a clean
