I'd just seal it, or paint it some reasonably nice color, and then... whenever he gets stickers, let/encourage him to stick them on His Bed.

We have a Brio table which is the Sticker Location. It keeps the things from getting stuck to any other furniture (save, pre-Briotable, the insides of certain cabinet doors), keeps them from being stuck on skin till they wear out and turn into curled trash that cannot be thrown away while she's anywhere around (and even then, she might wonder where it went), and satisfies her need to Horde Everything.

Little year-of-the-dragon kid...