Unfortunately, there is a lot of trial and error in figuring out what your body needs. Dyazide is a great diuretic for contest prep. It's much more forgiving that loop diuretics. If you pull too much, you can use carbs and a small amount of water to fill back out. The key is knowing how much you can take in without spilling!! Of course, your best bet is to avoid having to play that game to begin with. Over time, I've used less diuretics and come in just as dry as I had when I used them heavily. I rely on traditonal water and sodium manipulation and use just enough dyazide to take me to the next level. In my last show, I use 1/2 tab at 3pm on friday when I cut water and 1/2 tab before bed that night. I woke up dry and full.
Cramping has been an issue for me in the past. I've been able to avoid it by using less diuretics. I also take a chelated mineral supp, as well as taurine. If I find I'm cramping on dyazide, the day of the show, I'll take in 2 salt packets along with about 1 cup of water. This isnt enough water to make you spill and you dont have to worry about putting sodium back in your system because you are already dry.