I'm interested in do cooking the next time we go camping and I'm wondering about chimneys. I've never used one, know nothing about them but would like to try when my new do gets here. So, I looked on Amazon and saw collapsible chimneys but neither model has any reviews. anyone has used a collapsible model? I figure the extra space would be a bonus when transporting in the pup. Anyone used one or want to recommend a chimney?