I used a bag of popcorn in mine. It does not pop, and smells yummy. I use it when I sew in the winter to keep my little tootsies warm. I just put it on the floor next to the pedal so I can warm both feet at the same time. My main problem with doing this is that then Sweet Tater, my Chihuahua sits on my feet and makes me sew too fast. She likes it, too!