I hope this doesn't come off as too negative:
I've never really been impressed with the "cotton-ball-&-petroleum-jelly-packed-into-a-straw" concept because a simple stick of fatwood seemed better to me in every way. Now that I see fatwood dust packed into a straw, again, I have to say that a plain old stick of fatwood again seems better to me in every way.
How much more fatwood could you carry in the same volume, in pre-saw-dust form? Perhaps ten times as much? How long does it take to scrape enough fatwood from a stick to start a fire? I'd say about 5 seconds in good conditions, perhaps 8 to 10 seconds in bad conditions. So, I don't really see any speed advantage to cutting open a straw, compared to shaving a piece of fatwood. Which is more durable, and better protected against the elements? I'd say a stick of fatwood beats the straw full of shaven fatwood handily, in terms of resistance to breakage, and in terms waterproofness.
So, what is the advantage of the straw versus just a stick of fatwood? I have a hard time seeing one, but I have an easy time seeing a number of disadvantages.
Having said the above, "fatwood-dust-filled-straws" is fresh and innovative thinking. Good on you for your experimentation!