If you lose almost all your water weight and clean your self with a laxative how much poun/inch will you lose?

So i have a tape test soon two days. and dont say just run to lose it eat right ive been doing all of that and its working.. thanks... so im border lining this tape test i have to be 26% BFP or less and im right on it. i want to lose an inch or two and that will make sure it wont be a prob. So im right were i need to be but i want to be on the right side of the border. get what im saying? so i will eat light next two days run in a sweat suit and take a laxative. should work right? please help me out to cool my jets, im just looking for a way to hide an inch or so while i suck my gut it. any other tips i know this is not healthy but its a one time thing i still run like crazy every day. thanks