@sweethighland I've had my pillow for at least 2 or 3 years, and I've checked my order history, but can't find it. Amazon may not sell it anymore, but I'm sending two links that are similar to the one I bought. The one I have can be washed. I actually washed it again last week without any issues. It does take a while to dry in the dryer, but I want to keep it clean, so I put two pillowcases on it every week when I change our bed sheets.
https://www.belk.com/p/serta-comfort-curve-refresh-foam-pillow/0438745301036.html!!!!x!!!&campaignengineid=GG_23461354948&adengineid=&adgroupengineid=&ogmap=SEM|PLA|GOOG|PLA|c|TOP|||||23461354948|&gclsrc=aw.ds&gad_source=1&gad_campaignid=23456820884&gbraid=0AAAAADi6qOKzh8uI9oKXlHrAGxOtmUvGb&gclid=Cj0KCQjw2_TQBhCnARIsAF3-XhyFkOYBt7OSY-Y6MlrnbjtyFp7f1IL3fBi2RWObWtmwcLBfyrXLDJ4aArsfEALw_wcB
I also found this one from Amazon, but it is not exactly what I bought, but similar.
https://www.amazon.com/DreamyBlue-Adjustable-Combination-Alignment-CertiPUR-US/dp/B0DR9W4J8P/ref=sxin_11_pa_sp_search_thematic_sspa
What has helped the most is the electric adjustable mattress for our bed, which is pricey. I bought the pillow first, but not for sliding down. My neck was bothering me, and I thought this pillow would help, which it did.

I hope this helps. Sorry, I could not find the exact pillow on Amazon. These two links are close to what I have.