Great idea, but I think that you are doing one thing wrong. In a house/building full of smoke, you won't be able to walk around, there will be too much smoke for you to breath. You need to get down on the floor, as low as you can go. So I would suggest that you do all of your practicing on your hands and knees, crawling as low and fast as you can go. Then have the entire family practice crawling in line, possibly with a hand on the ankle of the person in front. You, of course, will be leading the pack...