Some trick how to clean mocrovave.

Put a mug of water and microwave it for 2 minutes( it also helps to add a bit of lemon juice if you have it). Let it sit in the micro for 5-10 minutes, don't open the door! The steam from the boiling water will loosen all that hardened on gunk.
Here is another method of how to clean microvaves: Take a cleaning product specifically for microwaves that was a disposable cloth with cleanser on it, similar to Windex or 409. Heated the cloth in the microwave for 2 - 3 minutes. The steam from the rag softened the yucky stuff. Then wiped out what was left with the warm cloth.