Any bleaching reagent should be an oxidant .... so the surface of aluminium which is shining glossy should loose the shine, since the oxidant is removing layers from the foil's surface and destroying the smoothness of the surface.. . PS: Potassium doesn't react with gasoline as long as this gasoline is dry and doesn't contain alcohol (ethanol) ... it is kept best under a gasoline-type liquid called petroether in order to prevent reaction with humidity from air .... is funny to laymen: potassium will burn when put into water and be extinguished when put into oil/gasoline