I have a blaze king Ashford 30.1. Was getting ready for the burning season today and swept the chimney. Its 6 inch and I have always used a soot eater. I take the section from the stove to the ceiling box out and sweep from the bottom up. When I did that today, there is about 4 feet of chimney that didnt get as clean as I would ( 5 to 8 feet above the stove.) Every other part of the chimney I can see clean metal. What should I do? Going from the top down isn't an option. Is there a way to push a brush from the ceiling box up? Looking for any suggestions. Thanks.