After paying a company $150-200 for years to clean my chimney, I sat in and watched them use a drill to drive spinning rods up from the bottom, rather than sweeping from the top down. Top of my roof is 2 stories and steep. I won’t go up there. I said I can do that if I find the right equipment. I found a drill sweep set on Amazon for less than $100. I used it for the first time and was very happy with it. I was skeptical about the flexibility of the rods, but they made the 90 degree up turn no problem. I did have to get the extra rods, my flu is 36 feet. It paid for itself the first use.