It is possible to clean the underside of a mousepad and should be done with the same frequency as cleaning the top. Generally, this involves wiping down with a damp cloth or sanitizing wipe and then allowing it to dry completely before use. Attention to detail, meticulousness, and organizational skills are necessary when cleaning any surface like a mousepad. Doing so helps ensure that all surfaces are kept clean and free from bacteria which can cause harm over time. It is important to take this step seriously to maintain freedom from potential health risks associated with dirt and germs regularly.