I bought one of those things and have to admit it took a while to learn how to do it. I agree with whoever said, "if you can't do it at home you won't do it in the wild in bad conditions". So I would agree with the practice before you need it idea. I bought mine for a curiosity and possibly to add magnesium to primer mix as I reload 22 rim fire. I use ground aluminum which really helps the primer mix. I have burned both aluminum and magnesium shavings from machining waste in a wood stove. I have saved a teaspoon or so of magnesium powder for adding to primer but looked up the idea on the internet and found that mixing magnesium with red phosphorus is not a good idea. So it is still sitting. Living in Wisconsin, when we were kids we used to "go down to the river" in the winter. At our "disposal plant" (where the treated septic sewerage was dumped into the river) the water never froze and fish used to come there where we would shoot them with a bow. We had a camp set up there and had coffee pot etc. Would start a fire and put on a pot of coffee before starting. A few times it was colder than 25 below zero and windy. (They didn't use the term wind chill back then) But we noticed that it became very hard to start a fire at that temp. Newspaper wouldn't burn unless the fire was going already. We didn't know about good tinders etc. Solution? And my recommendation for carrying a fire starter? Matches and a pint jar of gasoline. Before you go nuts, it seems to me that at that temp the gas burned more like kero burns at normal temperature. Not quite but certainly not the big enveloping whoosh of a gasoline ignition like you get in the summer. (Many know what I mean there) Anyway, getting serious again. Just a reminder, lighting a fire in bad conditions, under duress is A LOT harder than doing it in your back yard in the summer.