The outer cover has an anti-stain treatment that allows stains to be removed by wiping with a damp cloth and rubbing gently in a circular motion. Once dry, brush with a soft brush.
If it needs to be washed more thoroughly, unpack your mattress and follow these washing instructions for the cover:
Wash on delicate cycle at 40 degrees max
Use neutral detergents
Do not spin-dry
Do not use bleach or disinfectant products
Do not tumble dry
Do not dry in the sun
Do not wring
Do not iron, but if you do, do it inside out and at a low temperature