I just use a clean cloth, spray the WD40 onto the cloth and rub the amber wall. You'll need to keep moving to a clean bit of cloth or you'll end up re-staining where you've cleaned. Then buff up with another clean cloth. Some tyres are just beyond anything but this works well on grease, oil, rub and finger marks
Rubber hoods are the same process but the old toothbrush is handy for getting into any indentations. Just make sure you put the toothbrush back before the wife notices