a steam roller (of decent sizes) will choke just about anyone.... mine was literally unclearable, until i shortened.... i stil can't clear it (and i'm a 8 year smoker) but i'm sure there's someone who can... i can ALMOST do it, just not quite (there's been a few people to claim to clear it... but when i say clear it, i'm talking about filling it up milky white, then without moving your mouth away for a breath, clearing it, so absolutely no smoke is left, and holding in the smoke for atleast a second... the last time i tried to clear it [before shortening it] i puked, not like got nasueas... hit went in, and instantly puke came up.... i didn't even gag or anything it was weird!)