This is the protocol we used for Brent his last match. Also works for that one photoshoot or wedding of your ex you want to make regret ever dumping you.
7 days before weigh in:
Drink a lot (4-5L daily)
Also called water loading
2 days before the weigh in:
Eat low sodium
Then drink less (2L 2 days out, 0-1L the day before the weigh in)
Take bath
Work out with the heat to 30°
Sauna sauna
Keep sugars low.
Eat chicken and greens and yogurt
Or squid jerky, shrimp and yoghurt.
Some rice or banana (50gr) to keep you going.
Objective is to deplete muscle glycogen
Empty your bowels
Drain fluid
Each day you weigh in before and after the training
After the weigh in you drink a sports drink or two for electrolytes (minerals and salts) and eat Onigiri the moment you step off the scale.
Then shoyu udon to replenish muscle glycogen further.
You want to increase minerals, salts and muscle glycogen.