A piece of innertube about 1 inch square. Light one corner, put under tinder. All done.
So it's pouring rain and all you have to do is whip out a 1 inch piece of inner tube,light one corner and toss it under your tinder ? I guess I need to go back to the drawing board because it's never been as simple as that for me. I must have been doing something wrong all these years.

Are you lighting the innertube with napalm ?