I'm just catching up on this thread, but I'd like to add a couple thoughts about some earlier posts. There's nothing wrong with a former smoker deciding to vape, even if he/she quit a long time ago. I quit for a long time as well, and eventually returned. Perhaps I was in a low stress situation when I quit, but when stress happened I got back into it. Or perhaps (my personal favorite theory), I never really wanted to quit in the first place.
I would go around angry and bitter for years on end. It might sound silly, but I really held a grudge against the world for forcing me into this stupid decision. I liked my habit. I still do. In the end, I wasn't a former smoker, I was a hibernating smoker. If I had vaping back then, I'd have never given it a second thought.
There is a very calming sensation from vaping that mimics exactly what smokers get from their habit. That's nothing to shy away from. Embrace it. Perhaps embrace it at 0 nic, but embrace it. Personally, I'm tapering down. I'm at about 9-12 mg now, I guess the obvious next step is 6. But that's all water under the bridge. The analogs are gone, and that's really all that counts.
If the guy is still curious, then he's hibernating. Hook him up with vape gear, and don't view it as a quitting tool at all. It's a relaxing, therapeutic activity you can hang on to as long as you damn well feel like.
Wes