This step is optional but recommended. If your cleaning a white shell controller follow these steps for the front shell also.

If preserving the sticker is important to you then take care and be gentle when washing the sticker on the back cover. Use gentle pressure with your fingers in this area.

Sometimes there are "trouble spots" or dirt patches on the cover and can remain after you wash it. Take note of these spots and pay extra attention to them when washing. If they remain, even after a vigorous cleaning use a Qtip and rubbing alcohol to try and remove the spot. If a Qtip doesn't work simply use it to wet the trouble spot and use a

plastic prying tool to scrape it off. Sometimes they require significant force to remove and the plastic tool doesn't scratch the cover. Nail polish remover can be used here but I don't recommend it.