OK,

So it seems I really have problems bringing a whole gallon of fuel to the field, my bag isn't big enough.

Just what can I use to store fuel? I am about to finish the bottle of L'Oreal shampoo, it is 500ml, it looks like it could store my fuel, but I am not sure. And would 500ml be enough for a OS 50 FX? Assuming the tank that I use is regular sized.