Whether one person uses it or not,.....germs , siliva, crud, it should be cleaned as it is an essential piece of gear in your rig. Just the same as cleaning your keyboard with a dry/damp paper towel weekly also as the buildup of hand oils, and air particles build on the keys & the case,....something about a squeaky clean keybed, inside speaker horns etc,  that turns me on   

 lol.....
rule of thumb,......If You USE IT...... CLEAN IT!!  
