Sauna
It would be part of my Regime. Lets say I need to do 12lbs in 4days i would just go in 20mins one day, skip a Day and go 20mins next. Even though I personally have lost 7lbs in one day. Yes fluids were definately limited after, it take skill to measure to the oz it takes to keep it off and not to get de-hydrated which can happen Quickly.
There should be some guys that incorporate the Sauna into their Regime. When I did MMA in Detroit we would weigh in and then Eat. Carbs, Protein, I'm talkin my Usual meal would be 4-8oz Chicken Breast with 4oz Green Beans. After Weigh in we would go to the Sizzler, Ponderosa, some where you can get a Steak but all you can eat salad. Same with Wrestling.