The post above is the truth. All you can do is suggest he try it; provide him the means to try it, (an "E-cig and E-liquid). And tell him my story, one who was successful at quitting smoking, then quitting
vaping. I smoked for more than 52 years. I really didn't think that I would ever quit. But, once I tried an E-cig. . .I knew that I could switch from tobacco to vaping. It took me about 6 months of doing both, smoking and vaping, then I was solo vaping. Feb 6th was my last vape. Now, I don't do, nor miss either one. But, he has to want too. JMHO
Cheers,
otrpu