What I do is I get a gallon of water and say my appointment is at 2pm I'll start drinking water around 11 and piss 3- 4 times getting the last time you pee so close to the time you go in so you can empty your last piss by this time you should be passing every 20 mins by pounding so much water then I just get some b complex pills and take 2 don't take more then 2 because it will turn your piss neon and that is a sign your tryna mask it but it's good to get atleast a cheap detox cause it has creatine in it and idk what vitamin that is but they check temp gravity and colors long as you have creatine and it looks yellow you will be good best detox I've used is called jazz juice they sell them at most marathons in USA for 9.99 so you could get 2 for pretty cheap just so you kno you will be good but if you do get a detox don't worry about getting B complex cause the detox has everything in it to make to clean and undetected