I will always remember the thing I saw on TV once, that put me off smoking for life. It was so bad, that even when I told my friend about it - only using words - she immediately quit smoking and hasn't had a cig since!
It was this video of one of the tube-like parts of the body (I don't know what it was - windpipe/gullet or whatever) that used to belong to a heavy smoker before he died. The person had it in their hands and then they pressed their finger against one end of it, pushing up, if you get what I mean. Well...just imagine a small rubber tube filled with a mixture of baby sick, porridge and yogurt...and it all being squeezed out.
That was the mucas and other shitty stuff that had collected in the guy over the years before he died. I swear I will never forget that image, it was absolutely disgusting.