My daughter made some of those very things for me recently. We used them as I taught her how to build a fire. They worked well. You have to tear them to expose fibers, which you then light. We used a Bic so I'm not entirely sure they would light easily with a firesteel. I suspect the long, juicy fibers of a PJ cotton ball would light easier with a firesteel than the wafers.

In the JERRM's article they timed the wafers at 4.5 minutes. My homemade PJ cotton balls burn about the same amount and are easier to make. I do think the volume of material (and weight) is about the same between the wafers and the PJ balls.

The only advantages I see to the wafers is if you want something that packs flat and doesn't make a mess on everything it touches.