Will my AirPods be ruined if they are dropped in water or accidentally left in the laundry?
No, AirPods are not water resistant.
Officially Apple has not made any claims regarding AirPods being waterproof or water resistant. It is recommended to keep AirPods away from water as much as possible.
That being said, AirPods are designed for use during workouts, which means they could be exposed to sweat. Some have even gone so far as to submerge AirPods in water and run them through a washing machine, with no ill effects.
Keep the AirPods away from water as much as possible. If they are accidentally submerged, you may get lucky afterwards.