i have found one use for the drill method.
when i had a top exit 6 inch flue into 8inch chimney it was fine to just pullthe bricks out and wedge the brush up.
now i have a rear exit 5.5inch flue into 8 inch chimney…… try getting an 8 inch brush round there with a standard drain rod…..
although in that scenario i just go onto the roof and sweep the 8 inch down to the flue -then use a smaller brush for the 5.5″ from the top.
open the door and sweep…. how ever the flexy spinny shit would let me do it from inside the stove negating going onto my roof….which would make me happy – im not exactly over the moon to be going onto my roof twice a year..