Most Spas have pillows/headrests. We recommend not leaving Spa pillows in the Spa unless you are in the Spa. This is due to the mold that tends to grow inside when the exterior is compromised and water enters. Spa pillow manufactures insist they last 3-5 years but our experience has been 18 months to 3 years.
What we are now experiencing with pillows that we did not in the past is pillows that disintegrate. There are 3 Spa manufactures pillows that do this and possibly most of the generic Spas. We recommend not using those pillows at all. When these pillows are used the disintegrated material forms spots on the waterline and these spots stick as strong as a bright orange parking sticker. In one case it took several months to eliminate the spots completely. We can only guess that pillows are made with lower grade material as prior to a few years ago we never saw this happen.
Please let us know if you have any questions about.