What do you clean the inside of a refrigerator with?
Use baking soda in warm water. Rinse well with clean rag to remove gritty feel.
You can also use a mixture of vinegar and water, or bleach and water, or ammonia and water. If you use the bleach or ammonia, be sure to wipe down all surfaces with warm soapy water. Or, you could just use the warm soapy water.
I would first take of the plug, take out all the contents of the fridge and then get a sponge like thing [whatever you use to clean dishes is fine] and put some dish washing liquid in and pat the whole inside of the refrigerator and then wash it out with a couple of paper towels. However if you are talking about the inside of a fridge then same thing with the sponge and dish…