Supermark,
Ok. I tried a few experiments. (Why don;t we have any cotton balls [I'm asking my lovely wife]?) I used these round cotton swabs she bought. They're the size and shape of a thin oreo cookie.

I coated two with vaseline (that was messy) and two with parrafin oil. Then I rolled them up like a tortilla.... tightly... and cut them in half so they look like the little fire tinders in Ritter's PSP. (I know they're not as good as that stuff, because it's compressed, but they look like them.) They both took the very first spark from a Doan's flint and, without even blowing on them, flamed and burned. Both burned a nice flame for more than 80 seconds. Near the end when I blew on them (simulating windy conditions), they kept right on burning. So..... taking your advice a little further.....

I made two more batches each and rolled them up in wax paper. I used a hot glue gun to seal the paper on the last part of the roll. They look just like Ritter's tinder but probably not quite as effective. However, you could just unroll the paper, leave the tinder on top, and when it burned it would also burn the wax paper for a little more flame and heat.

I think the vaseline and waxpaper ones would be more water-resistant, but it sure is easier with the parrafin oil ones. I guess I'll have to do some submersion testing.

Thanks for the advice.