Would you like fries with those boogers?

Essentially, he claims that since children need to develop immunities to bacteria, etc, then what better place to get them than right there up your nose? After all, a vaccination works the same way. Small bits of the bad stuff are taken into your system, and your body learns to fight it off while never actually facing any signifignat threat. Based on this theory, one could postulate that we could theoretically develop resistances to all of the world's bacteria. By this guy's math, booger-eating is a step forward in human evolution.
Let's talk about this for a second, shall we? I mean, it may be a perfectly valid argument from a medical point of view, but isn't this exactly the sort of thing that keeps the rest of the world from taking Australia serious about anything? They could put a man on Mars next week, but all the

But it isn't a valid theory, even from a strictly medical point of view. What this guy fails to realize is that developing resistances to everything isn't necessarily a good idea. If all we needed was a way to fight off infections, we could all pop antibiotics, which would be freely available without a prescription. They require a prescription for a reason. Not because someone might try to catch a buzz on amoxicillin, but because using them when you don't need them allows you to build a tolerance to them, which in turn means that the infections and diseases eventually become resistant to antibiotics. Yeah, it works both ways.
Leave well enough alone. We, as a global culture, pick our noses exactly the right amount to maintain the balance. If you want to destroy the world, you'll have to find a different method. Personally, I think that having Jeb Bush run for president might be a good start. Not only would he do a typically Bush-esque job of completely screwing over the US (and the world), but if he's anything like his brother, he'll no doubt support the whole nose-picking thing.
PS - Yes, that's really George. Big surprise, huh? Anyway, click the picture for a moving version from the original video.