Swore by wire brushes for 12 years, then a 3 dollar plastic card changed my whole flue routine
I always used a wire brush on light glaze and figured it was good enough. Last month on a job in Gary the glaze kept smearing and the brush just polished it. An old sweep next to me handed me a stiff plastic scraper card and said try this dry first. Two passes and the glaze popped off in flakes, flue ran clean in about 15 minutes instead of 40. I was wrong, the card gets under the glaze without burnishing it. Now I carry three of them. What do you all use on light creosote when the brush just smears it around?