We all know, or should know, that smoking traditional tobacco will kill you. Yes, it will, and quite unpleasantly. I've watched several people die very miserably and painfully who really thought it would never happen to them.
So, along comes vaping. Smokers think Great ! I can carry on, just modify my habit. So instead, they are inhaling something that they are not sure exactly what it is, or exactly how it is delivered. It is so easy believe and trust something that you want to believe and trust.
Here you are eat this. What is it? Never mind just eat it. Doh, ok
I used to smoke, lots. I gave up. No substitutes. No vaping. No patches, tablets, or whatever. A few weeks of misery for me and my family, and then all done. I am healthier, financially much better off, and I can be really very sanctimonious about it all.
Sorry to be a bit blunt. I genuinely hope he's ok, but he should just give up.