1. Hand wash the polishing cloth with dish soap and water.
2. Rinse thoroughly.
3. Allow the polishing cloth to air dry for at least 24 hours.
The instructions have been on Apple’s website for at least a few months, according to the WayBack Machine, but despite a handful of reviews or articles mentioning them, I hadn’t come across them. That’s really a shame — other people who also hadn’t known about the instructions might’ve been throwing away their priceless polishers all because of a little grime, wasting $20 simply because the cleaning instructions are buried on a support page instead of being included on a tag, or embossed on the cloth itself. (I would also settle for prime placement on the Apple home page, where all people of the cloth spend their day.)
The instructions themselves are also a little disappointing — ultimately, Apple is telling us to wash the cloth like we would any other delicate fabric. At least it’s back in stock.