Steam can soften dried microwave splatters so they wipe away, but there is no need to boil water for a long time. Use an open microwave-safe container, heat in short intervals, and let the steam sit with the door closed before wiping the interior, unplugging first if the manual recommends it.
Use an open microwave-safe container
Put water in a stable container with room for bubbling without overflow. Do not heat closed containers or sealed jars because pressure can build dangerously.
Heat in short intervals
Start with a short heating time and stop when there is enough steam to moisten the walls. Water can superheat in some containers, so do not jolt it or put your face close when opening the door.
Let the steam soften the residue
After heating ends, leave the door closed for a few minutes so moisture can work. Then remove the container with protection if it is hot and wipe with a nonabrasive cloth.
Wipe the tray, ceiling, and seal without flooding openings
Remove the turntable for washing if the manual allows and wipe splashes around the door seal. Do not pour water into vents or remove the cabinet; an electrical odor or persistent arcing needs service.
Sources
- American Cleaning Institute — Cleaning Tips — General household-cleaning practices and responsible product use according to labels and surfaces.