Use cleaning agents that won’t hurt your hands with any leftover residue; we recommend a 70% isopropyl alcohol solution (aka rubbing alcohol) for quick disinfection.
For dry messes, you can vacuum dust, fur, and other dry material off of an installed KeyboardMask.
Even with KeyboardMask installed, we don’t recommend sticking your keyboard in a sink, because the USB-C port is uncovered and can be damaged..
If you have a lot of finger or food grease on your KeyboardMask, you can take the KeyboardMask off your Magic Keyboard and wash with soap and water, then dry it before use.