Morning Bob.
I had one of these fall out of an estate pipe I recently received when I was pulling out the half-smoked bowl that had been left behind. My eyebrows were raised, as I had NO idea what the hell it was. Subsequently, I picked up a pipe rack with a drawer at an antique barn and there was a small packet of these in the drawer (along with about five pipe tools and three vintage lighters). Let me know if you want to experiment and I'll send you the packet of Philtpads.
For the record, I think "Sharrow Philtpads" might be one of the funniest/riskiest/dumbest names for a product I've seen in a LONG time.
-- Pat