You guys have missed the most important remedy of all. Drink 2 gallons of water a day and you'll see how your body reacts after a couple of days. You'll be extracting water like there's no tomorrow. On your beach day, quit drinking water 6pm the night before, you'll wake up on the morning dry as a wistle. Refrain from drinking the rest of the day and you'll remain dry as fuck. This will only work for a couple of days though or else your body will reverse and start storing water again..
It's just natural manipulation.. A pre-contest trick we all use....
Good luck.....