Just found a Youtube video on this. It is funny as most people on this site will complain about how terrible it is to make a fire using Mg shavings off of a comboMg/firesteel. But this is NO differant as you have to protect you tinder. I am sure that birchbark dust would blow away very easilly. But it was a good thing to see.
Congrats on your fire now your a master of your domain.
cheers