I have 6" double wall stove pipe coming out of my Jotul F3CB then it makes a 45 deg angle to my outside chimney. I brushed my outside chimney. My question is: how important is it to brush my stove pipe? Wont the temps be so hot that creosote will not form? I've never had it apart so I'm not sure how to take it apart if it is recommended to clean it.