Never thought of that one. However, every pipe cleaner I have seen have been made from a synthetic material. Wouldn't those just melt and not burn very well? I am thinking of when you burn a cocktail stirring rod with a candle. Done this many times at weddings!
However, if it is the petroleum jelly burning then I understand it. If you just carried the jelly, you could smear it on your kindling and not worry about the pipe cleaners. You could get a big glob on the end of a stick and you would have a super match! You would also have the jar of jelly for other uses like lip balm ect.
My fire skills are to the level that I seldom need a firestarter. I can usually find plenty of dry natural tinders to get my fire going. When I cant find enough due to weather, I use my back up piece of bike inner tube. When ignited with a lighter these babies burn long and hot.