I've tried everything discussed so far, and am happy with PJ/Cotton..to catch a spark and then light tinder. I have soda straws stuffed with the PJ/Cotton stashed all over my kit. That being said, just for the "back up" knowledge, I tried out the following (remember, my criteria was to catch a spark and then flame enough to ignite tinder):
1) Neosporin - on a piece of 4x4 gauze. Worked fine. The Neosporin was in a foil pack. It has a petroleum jelly "base" anyway.
2) 4x4 gauze pad rubbed with Chapstick. Worked fine. Again, some of the lip balms are petroleum based, some are carnuba wax based. Both have worked fine for me.
3) Alcohol Prep Pad (alcohol, not benzalkonium chloride) Just opened and hit with sparks.. great blue flame and it started tinder just fine! These little pads are stowable everywhere!.

If I use a match, lighter, or some other actual FLAME (not spark): I light a ranger band sized strip of bike innertube. This will start fairly poor tinder. Stinks.. drips hot burning rubber everywhere (not a disadvantage, though).. but try it!