I stopped using my shop vac on creosote and tried a $12 hand brush from a hardware store in Tulsa
I used to hit every flue with the shop vac first thing because it felt faster and cleaner. Last Tuesday on a two story colonial with a bad glaze problem, the vac just polished the creosote into a shiny shell. I grabbed a stiff wire hand brush a guy in Tulsa sold me for $12 and worked it in circles for maybe 4 minutes per section. The crud came off in flakes and the flue pulled way better afterward. Now I want to know what brush you all keep on the truck for the stubborn glaze, because mine is already losing bristles.