It will work. What you can do is take a piece of typing paper and fold a crease down the middle of the paper. Then take some of the FFg in your fingers (dry and clean hands) and grind your fingers together over the paper. It will reduce the size of the granules. Then when you have enough ground up, lift the paper up to make the crease your funnel and put that is a separate bottle. Use that as your primer. It will do just fine until you can get some 4f or 3f.

90 grains of Goex 2f and a patched roundball is the sweet load of my Flintlock Lyman Trade Rifle... good luck, keep your agate and flint sharp and you are in business.