So, are they reusable?

Yes, they are reusable.  Laundering Guidelines- Machine wash cold with like colors. Do not bleach or use softeners. Tumble dry low. Do not iron.  Or Hand wash with mild detergent. Do not bleach or use softeners. Lay flat/hang to dry

Service Life - The service life of this product will vary depending on the application and type of care administered. This product should be replaced immediately once a critical or major defect (as defined below) is noted.. Holes/tears, Dimensional or weight nonconformance, discoloration or other defect.