Interesting enough, I sometimes extracted wadding plugs and felt plugs out of some loaded smoothbore flintlock barrels over the decades. They were placed on top of the ball to obviously keep it from rolling out.
In 17th century loaded military barrels I sometimes discovered very fragile wadding pieces from newspapers or books, especially in wheel-lock pistols. They may have been used to form the paper cartridges. A few torn and crumbled pieces of printed paper I found in an untouched leather holster for a long wheel-lock pistol of ca. 1620; the text was German, printed in early 17th century types, with the date 1621 clearly visible. This must have been from a paper cartridge because it contained traces of black powder and was found on the bottom of a lateral compartment containing a wooden block drilled for four paper cartriges, the wood heavily damaged and with considerable remains of black powder on the inside walls.
Even for me who has actually seen and handled a great lot of unique things, this was so unbelievable that I made a photo documentation (sadly not of the paper fragments) which I attach. The length of the holster was 64 cm, the caliber of the bores ca. 12 mm each.
This considered, I now doubt myself that those short strands of tow were actually used as a wadding because the paper of the cartridges would have served that purpose. I think that Manuel's thesis is more convincing than my own and that tow was used for cleaning the priming pan of the match- or wheel-lock musket.
Extremely demanding, these discussions, thank you so much!
With all my best wishes,