Ok, I tried searching for an answer, but I was unsuccessful. I hope this isn't a really stupid question, because it would be great if this works. I read, on some website by some unnamed source (I was stoned, late at night, can't remember where), that the tube in a dbv was rated at "twice the temp. of combustion". If that is so, would cutting an approximately a 1/4" section of the tube and shoving it to the bottom of the stem of the dbv to decrease the diameter of the bowl, be a good idea, or would it poison me?