I have a Montpelier medium wood insert that was installed last summer. The first thing me and my brother did was disconnect and pull out the stove and roll it on a movers Dolley that i built the same height as the hearth so i can install a blockoff plate later. Then we both went on the roof and pulled off the cap and pushed the poly medium brush part way down in the 6 inch liner with a rope attached just in case. I went back down inside the house and tied a plastic bag to other end of pipe to catch all the junk and a that point my brother screwed on the first section of 3/4 gray electrical pvc pipe and pushed the brush down a couple of feet but could not pull the brush out and i had a panic attack because i thought you should be able too well it turns out that the brush can only be pushed in one direction and cannot be backed out and with 2 passes down the liner i only had about 2 coffee cans of junk. I would say i burned about 2.5 cords of wood mostly at night and on weekends. My chimney is now cleaned and the next step is to make the blockoff plate to improve the heat output.