It's been a week since I started my little experiment. I reckon it's time for an update.
So far, I've noticed very little difference between the nails swiped with vinegar and the ones not pre-treated. There is some wear along the edges, but nothing out of the ordinary. The control foot (the left one) has roughly the same amount and type of wear as the experimental foot.
I'll update again in a few more days, but so far, it looks like this myth will be busted.