Wash means just run it through tap water for few seconds and then wipe it clean with towel.
You’re misinformed, this is what Apple recommends direct from their website:
https://support.apple.com/en-us/HT207123
- Use a soft, slightly damp, lint-free cloth—for example, a lens cloth.
- Avoid getting moisture in openings.
- Don’t use cleaning products or compressed air.