I doubt mentioning DMT to him is going to sway him at all. These experiences are very personal and very real. It will take a lot more than that to coinvince someone who believes they had an NDE that it was merely a drug trip. Also, some people fear not being able to trust their senses.
Even if the open windows of science at first make us shiver after the cozy indoor warmth of traditional humanizing myths, in the end the fresh air brings vigor, and the great spaces have a splendor of their own - Bertrand Russell
