I've found that as I smoke my cobs, once I get down to about the last 1/4 of a bowl, the draft hole is so large that I end up pulling ash in from the bowl. Once any blend I'm smoking gets to this point, I'm just tossing it. I enjoy smoking all of my tobacco when I can and when it will smoke to the bottom of the chamber, but when this happens, I just know I'm better off knocking out the rest, watching that unsmoked tobacco just fly away. I don't bat an eye when it's something like PA or CH, or some 1Q, but if I smoke something I value a little more than those, I feel like I should smoke them in something other than a cob just so that I can finish my smoke on a happier note, and not one filled with a mouth full of ash. So, are there any blends that you will not smoke in a cob if you can help it?