Welcome to SR!
I recently read this from an addict and it might apply...
When i was main lineing (needle) opiates, when I did'nt have something i would just cook the water and shoot that. it is called being addicted to the needle, there are many different addictions in the addicts life.(ME)
Being an alcoholic...I had never heard of this nor have I heard of Comet sbniffing.