Good idea, I have been thinking about doing that, although some of our doctors and scientists here seem to have different opinions. But hey, isn't FR great? Where else could a guy get such good advice about such an important issue?
OK, so we've just about hit upon every possible bit of advise possible, eat the potato first, eat the potato last, eat the potato in between, get stoned, drink bitters, work out, eat a lot before, starve before, drink water, no water, etc. Having witnessed Kobayashi's 2 Nathan's victory, I can tell you that the trick is the rapid consumption of the food, with a stomach muscle that is well trained in expanding and breathing at a constant rate to increase digestive tract movement. Also remember from the tv show on the history channel that you should try to stay leaning forward or just upright as long as possible, leaning back will decrease your stomach cavity size.
We're the same height and weight, and there's no way I could down 72 oz's. If you can, get the potato mashed, and eat it last. The carb's as stated previously will wreck your will power.