OMG!! That's awful.. Glad all is ok..
I have a couple that my MIL made. Ive been using it for years. I love it. Wonder if the bag being wet has anything to do with it not catching fire ??? ( yea I wash the potatoes but I'm to lazy to dry them and the bag gets pretty wet in the process )
Sorry to hear about your bad experience, and thanks for the warning..
P.s. My sister told me she cant put regular paper towels in her microwave, It catches fire on her..