I do lots of laundry. Lots and lots of laundry. One thing that has helped, plus saved Mom’s mattress many times over, is our supply of Save-A-Sheet mattress pads purchased from The Alzheimer’s Store. They are soft terrycloth backed by a pliable plastic or vinyl or something that holds up through many, many washings. And since the pad tucks in on both sides of the bed, it stays put. I have them layered both under the fitted sheet and again on top of it, to also protect the quilted mattress pad, which covers the waterproof mattress pad. Lots of layers-that’s the key.