No back alley's here, by definition they are criminals so the moral fiber is questionable at best. I am not often confronted with the stupidity of vaping but, on those rare occasions, I can confidently state that I know exactly what is in my liquid and it is not anti-freeze although my stuff won't freeze.
Reminds me of something. My current doctor is an amazing person, but the one before him was, well, irritating. I went for my first visit with him a few years ago and it went like this:
"Do you smoke?"
"No but I use e-cigarettes."
"Oh, we have to do something about that."
"Do we?"
He went off on me. He was so judgmental, so harsh in his assessment that I'm doing some sort of great harm to myself. He finally says "the bottom line is you have no idea what's in that liquid."
"Yes, I know exactly what's in it. I make it myself. I also build my own heating elements."
He looked up at me slowly, eyes wide open. Stared me down for a moment, then, eureka: "Wow - I must admit you clearly know more about this than I do, and if this is your only vice then you are perhaps the healthiest young man I have met in a very long time."
It was such an incredible change of tone. And every time anyone's ever said that kind of thing to me, I proceed to tell them I make it myself and 100% of the time it causes them to bow out of the conversation respectfully.