Unpopular opinion: I tried a cheap brush on a really old flue and it worked better than my expensive one.
I mean, it was a $15 nylon brush from the hardware store, and I was just trying to clear some light soot in a 1920s house. The thing is, the bristles were way more flexible and got into the weird mortar gaps my stiff wire brush always missed. Has anyone else had a cheap tool surprise them like that?
Totally get that with old houses. My grandpa's place had these weird, uneven bricks in the basement. Bought a fancy scraper for paint, but a cheap plastic putty knife from a gas station bent just right to get under the loose bits without gouging the soft brick. Sometimes the simple stuff just fits the weird job better.
Old bricks" are the whole point though. That weird fit and handmade look is what gives an old house its soul. A new perfect brick would stick out like a sore thumb. The fuss is about keeping the character, not just patching a wall.