Try a ginger root bath...get some ginger root, slice it up and tie it in a sock, toss it in your bath tub and make the water as hot as you can stand it. Try to submerge your self in there for about 45 min to an hour....if you can take it. Also, try a glass of red wine before you get in.....you will sweat your ass off. Do this the night before you weigh in. Do not drink any water until you weigh in. Just drink water or gatoraide after weigh-ins and you will be fine.
I got this off of monstermuscle.com....Rya n Kennelly does this before a meet and I have tried it. It works!