Coffee grounds absorption.

Used coffee grounds, when dry, can also act as an odor absorber in a microwave. Leaving a bowl of dry coffee grounds inside the microwave overnight allows them to neutralize and absorb stubborn smells. Similar to baking soda, coffee grounds are a natural deodorizer. This method is particularly useful for strong, lingering odors, and it will leave a coffee scent in the microwave, which can be a pleasant alternative to food odors for coffee lovers.