KEETSA MATTRESS COVERS ARE NOT REMOVABLE OR WASHABLE - despite the presence of a zipper on some models. If you happen to stain your mattress, it is best to spot clean the area using a small amount of warm water and mild detergent. Use extra caution not to get the foam layer wet; this can damage the foam. Most importantly, make sure the cleaned area is completely dry before adding your bedding. You can use a hair dryer to dry the area off more quickly.
If you need to clean a larger area or the entire mattress, please contact a furniture/mattress cleaning professional.