It depends. How big is your big foot? We all know the "special relationship" between foot size and the size of one's "unit". If your foot is decently sized, then there will be sufficient magic goo. If you have a girly, babby-sized foot, then I pity your putty fool.
That being said, I would guess some quantity between a teaspoon full and a texas mickey, depending upon the availability of the lone star longhorn. Anyway, the evolutionary future is in your hands.