The real problem here is that this sort of experiment is what the Mythbusters team WOULD NOT attempt.
Mythbusters tends to attempt spectacular failures where you can measure success or failure in terms of something flying into pieces.
For example, trying to destroy a car's engine by throwing it into reverse - that was a myth that supposedly had instant results.
The experiment at hand is completely counter to that philosophy. You can't excite an audience by blowing on a cartridge over and over, and you could need months before you see any progress.
Finally: Once again, it's gross and unnecessary.
I'll leave out the issue of sample size because, again, we know what's going to happen to a NES cartridge contact when it gets moist. It's going to corrode. If by some miracle it doesn't, you've goofed up your process somehow, like somehow obtaining a game that has a different type of contact pins, or not running the experiment long enough.
The only thing related to NES contacts that could be tested is how many blow/dry (hah) cycles you'd need to see degradation. But that's pointless for obvious reasons. Should I keep lighting up cigarettes until I die? I know I shouldn't start in the first place.