If I had some old gunpowder around I'd do your acetone thing, but the little I had we experimented by mixing it into the fatwood sawdust.
Someone gave me some old blackpowder.
I put it in some old prescription bottles, in a ziplock bag, with a bic lighter, that has the strips of bicycle tube wrapped around it. Add some tinder, and it is as close to foolproof as a person can get.
I have a few of the flint and steel type tools as shown, but while fun to play with, when I am cold, and my fingers are numb, like on a December elk hunt, I just grab the bic and start a fire.
