I wonder if, like filters, stingers are far more popular in Europe. All U.S. pipe smokers seem to say -- if Forums is any indication -- is that they pull the stingers out and save them in a ziplock or throw them out. Somewhere there are non-pipe smokers who find these and rack their brains trying to figure out what they are and if they should be saved, like some missing part that goes with something else.
The only stinger I use is in one of the old Kaywoodie Drinkless pipes that has the screw-in stem and attached stinger; now the Drinkless series has gone to push bits. But the stingers still live on. Somewhere, they must be left in place for smoking. Where might that be? Who might that be?