While I initially considered it more of a parlor trick, using a snack chip or other food for an emergency fire lighting tool does have merit. My bias toward this topic being duly exposed, let me offer some positive points on the aspects of this “survival” technique.
The main difference between a burning Dorito™ and a stone oil lamp is that the oil lamp tastes slightly more gritty—and is much harder to chew! Basically any food that will ignite and draw fuel from the cooking oils it holds could probably be ignited, at least with a match.
Question is, why would you want to waste a few snack chips, cashews, or whatever other combustible munchie? More importantly, a valuable resource such as a match or limited lighter fluid as a means of starting a fire? To his credit, one expert on an outdoor self-reliant website who conducted tests with various food items as tinder admitted that it had taken him at least 45 seconds to set a single cashew ablaze. That’s a lot of matches or lighter fluid! And, although I haven’t tried it, I’m pretty sure that such tinder is not combustible enough to ignite from a shower of sparks either.
My biggest question to those who profess this skill as critical, or even marginally useful is …what are you using to actually fuel your fire? What is your foundation of tinder; your kindling; and ultimately your long-burning fuel? Obviously there’s not enough wood or other material at hand to readily or directly ignite, or you wouldn’t be trying to torch your gorp. So what fuel are you going to be using to maintain your fire? You apparently don’t have any wood to shave into a feather/fuzz stick; and are all your other fuel options so wet you can’t even split or tear any apart to find dry fibers inside?
All that said, if matches were scarce and tinder was limited, perhaps the extended life of a food-fueled flame would buy you some ignition time to get the embers glowing. Tongues of blue-green flames lapping the air around a burning marshmallow could easily be shoved into the center of your tinder pile to trigger the inferno. This is not all that far removed from using a cotton ball swathed in petro’ jelly (or smeared with butter or cooking oil if we are staying in the food mode here) as an emergency fire starter. Likewise, a few greasy corn chips might buy you a broader, longer burn time than could a single match, or without emptying the fuel reserve from your BIC®.
It would be an interesting exercise to check out a variety of alternative tinder/food fuel sources. Select several likely “food snack tinder” samples and test each one for ease and speed of ignition, length of burn, etc. Maybe you will find one that would actually augment the use of a match in time of need, and serve a dual purpose as a tasty treat. While you are at it, see for yourself how easy or difficult it may be to light any of these alternative tinder sources with a spark from a flint/steel kit.
All that said, I must admit I’d rather depend upon a corn chip to light a fire than have to chomp on a self-lighting briquet for a snack. Bon Feu, mon ami!