I have, but I find they work best if you don't use them as is usually shown. I have best results if the 'open' part of the C shape is at the back of my neck.

I have, but I find they work best if you don't use them as is usually shown. I have best results if the 'open' part of the C shape is at the back of my neck. That allows the pillow portion to support my chin instead of the back of my head. Disclaimer: I'm fat, with a big head. Results may vary for skinny people.