Elaborate. I can't find any information on substance diffusion from the oral mucosa to cross reference with the concentration of formate that could be expected from 10^??? bacteria living in the crevices between your teeth and gums. It would make me feel a lot better to be wrong, since the differential diagnosis is significantly less grim with slow formate poisoning removed. I'd throw down that hundred bucks just for the reassurance, even suffering as I am with medical bills. From this.

And the bullet? I choose a BB, to shoot just your eye out. It's only fair :^)

(I wouldn't actually it's just a bit of dark humor for you)