Before I made mine, I read into all the fire issues and 100% cotton is a must. I decided for myself that I would be extra safe and so I wet the bag, wring it out, and then insert the washed potato. This is almost like steaming it and still comes out just as fluffy. I also only set mine for 2 minutes, flip over, 2 minutes, flip over, until done. No fires yet and I keep a close eye out.