Worst scenario situation? It doesn’t go very well and you've got to put up new drywall up or use some sort of planking/panelling to cover up the mess – either way, no less than you gained’t have popcorn any more! (go through far more here re: drywall set up) http://prbookmarkingwebsites.com/story4224602/5-easy-facts-about-remove-burnt-popcorn-smell-described