aldactone is not a good choice
A good protocol to use precontest for a saturday comp is (8-10am prejudging):
increase water intake significantly starting 7 days out from contest. drink upwards of 4 gallons per day. inrease sodium intake to replace what is lost with the extra water. Take 1.5-2 grams dandelion root and 2 grams of uva ursi the whole week along with the extra water.
Friday 10a.m. stop all sodium
4 p.m. 1/2 pill diazide (25mg hydrochlorothiazide/ 37.5mg triamterene)
8p.m. stop all water intake.
9 p.m. 1/2 pill diazide
2 a.m. 1/2 pill diazide
6 a.m. 1/2 pill diazide
Sip water the rest of the day
This is very similar to what dave palumbo recommends to his clients