Well, after several days of fan-drying and occasional wringing, the foam contour pillow I washed seemed to be as dry as it was going to get, so I tried sleeping on it last night. It wasn’t perfect but it was somewhat more comfortable than my other contour pillow is at the moment, and I got a reasonably good night’s sleep. Hopefully my newer pillow will regain some of its original volume if I let it go unused for a while, and then once the “rehabilitated” one starts to get too flat again, I can swap back, and alternate between them thereafter. Which would certainly be preferable to buying a new pillow every time the current one gets too flat.
I wonder if the more expensive “memory foam” pillows and mattress cushions that I see advertised on TV have the same problem, the foam getting more compressed and less comfortable over time. Naturally that’s not the sort of thing they’d admit in the ads.