Oh man, that's brutal. I swear by the solid rod brushes from ChimneySweepPro. Got the stainless steel one like five years ago and it just glides through. No fancy gimmicks, just a solid brush on a solid pole.
Ugh, I read some article last year about how those segmented rod brushes can come apart and get stuck. Total nightmare scenario. Makes the solid rod sound like the only sane choice. Five years with no issues is a pretty good review right there. Sometimes the simple tool is just the right tool.