DIAGNOSIS The removable fabric shell is a polyester blend. Liquids can stain and seep through to the inner mesh.
FIX Remove the shell by gripping the base and pulling it straight off. Use a damp (not wet) cloth with cold water and a drop of mild detergent. Blot, do not rub. Air dry completely before reattaching.
IF THAT DIDN'T WORK For set-in stains, you can hand wash the shell in cold water with mild soap. Rinse thoroughly. Never machine wash, dry, or use heat.
HEADS UP Do not use solvents, alcohol, or abrasive cleaners. They will damage the fabric and the adhesive holding the inner acoustic mesh. Never reattach a damp shell.