@Div I should read that article. I'm not disagreeing with you, but I truly don't think it's that much of a benefit. Sure, your body will be exposed to new antigens. But not nearly as many as if you were to kiss your dog or fall asleep with your mouth open etc etc. I eating snot won't really hurt you, seeing as we swallow 2 quarts of mucus a day, although, I still highly discourage the idea. Lets he honest, who really wants to see people picking their nose all the time? As for being dirty in the past, this is correct. However, we were not healthier per se. Look at all of the cholera that was contracted throughout Europe over time. It by no means is good to be a cleaning fanatic, as you kill off thousands of bacterium which can prevent the production if new antibodies. All in all, it is good to be moderate. Instead of picking your nose, just don't wash your hands after you're done using the rest room.
The ideas above are not sanctioned by many hygiene smart people. It is a fact that those who pick their nose are more inclined to be better in tune with their bodies.
Once I picked my Snout (snout since I'm a charizard), and you'll never believe what I found! It was Waldo.