I carry a carmex. one time as a test, I had it burning for 20 minutes: see below for my 2006 post:

Everyone here is familiar with the cotton ball / vaseline fire starter, I assume. You know it will catch sparks when torn open, and give some good flame for around 5 minutes. Recently, an idea came to me while I applied some Carmex to my lips. this little canister of lip balm in my pocket suddenly set off a light bulb in my head. I headed for the fire place to experiment after first grabbing my pocket knive, firesteel and a cotton ball. first, I opened the carmex, then with the screw driver on my knife stuffed the cotton ball down to the bottom of the canister right into the lip balm. of course, this displaced some of the lip balm, which I just slathered on the side of the remains of the cotton ball, leaving some cotton exposed to fray and catch sparks. ignition was simple with firesteel (or match/lighter). what happened next was a slow startup, I almost thought it was going to burn out. maybe a different installation of the cotton wick would help, but I've only tried once so far. anyway, it started to pickup in intensity, until after a minute or so was 4" tall. THIS CONTINUED FOR 20+ MINUTES! Better performance than I've seen for any firestarter, bar none and yet much smaller. the entire container also melted down to nothing, as well as it's contents (although it held it's general form as it burned down). This was so cool, I thought. I carry this stuff anyway. I'd be interested in any tests others run with blistex and other brands, as well as approaches to the "wick". try it, you'll have some fun!