I have a Quadrafire 3100i that is connected to 16' of 6" flexible stainless liner. I installed it last year. I need some help on cleaning it. I brushed my chimney with a 6" poly brush, from the top down. It was dirty but not excessively so. Then I opened my insert, vacummed all the cresote that fell down onto the firebrick. Then I used my hand and a piece of cardboard to sweep the flat horizontal area clean, above the tubes. I'm sure i didn't do a perfect job, but i am confident it is failry clean. Is this method acceptable? Or do I need to pull the insert to clean?