Yes, I have them in my bedroom. We had warped wooden window frames in this apartment building up until last year, and the windows could not be closed all the way all through the winter. We are talking icy wind whistling through the gaps.
They did keep the room warm, and no more whistling icy wind last year.
The ones I purchased were a heavy canvas sort of fabric.
They have a rubbery backing on them, and they did say dry clean only because of the backing, however, they lied. The dry cleaner said he tested a patch and he can't clean them without dissolving the rubbery backing.
I will try washing them with a delicate setting in the machine, which he suggested, and he says he can press them for me.