Tampons work great for cleaning shotgun
The quickest, cheapest & easiest way I have found is to take an extra-absorbent (heavy flow) tampon borrowed from my wife, pop it out of the applicator, tease it out a little bit with your fingers, apply your favorite solvent & then place it in the breech & use the rod to push it through the barrel. Make sure to use the same sequence as you would use with patches & use a dry tampon after using the solvent & then you may want to use a lightly oiled one for your final pass. You can get a whole box of generic tampons for a couple of bucks, and they have a lot of surface area, 2-3 passes & my barrel is usually gleaming. Hope this helps. -Toby.