The Kwik-shot soot stopper has worked for several years for us. We have a 22' stainless, double-wall chimney and, while we try to burn only seasoned wood, occasionally we hit a run of less-than-perfect wood. The use of this product has eliminated the rental of a lift platform to access the top of the chimney and we have been able to avoid hiring a chimney sweep. We constantly monitor the pipe for any build-up and a quick treatment with the Kwik-shot cures any issues. The only itty-bitty item is that after a cleaning, flecks of ejected soot are evident on the snow on the lawn. That's not a problem, just evidence that the product has worked. Good stuff!