Appreciate the great comments on interior masonry chimneys on an older thread. About to remodel and ready for new chimney but wouldn't have to be masonry. Considering a boxed in 6" metal up interior wall thru a cathedral ceiling (1) Could you thimble into it thru wall same as with a masonry? (2) What would the cleanout be like? I'm guessing it would be a cap/plug at bottom so you could run a brush all the way down through it. (3) With this type installation would you make front panel removeable so as to be able to examine chimney top to bottom occassionally?