Which side of the pillow do I sleep on? Customer Service Desk August 06, 2019 14:32 Follow The pillow should be placed “cap down” against your mattress. Related articles Is normal tap water okay to use in the pillow? My pillow leaking, what do I do now? What is the size of the Chiroflow® Professional Waterbase® pillow? How long can the water stay in my pillow before it needs to be changed? Comments 0 comments Article is closed for comments.