This is the government you're talking about though, and I have a relative that used to work at Lockeed Martin designing and programming missile targeting data and shit like that, so to be honest, I wouldn't smoke anything, be around it, drink water for a long ass time, plenty of Vitamin B12 ( I think it's B12, don't take my word on it. ), cranberry pills and whatever else.
Here's the link to the stickied thread for how to pass a DT.
http://forum.grasscity.com/seasoned-...w-pass-dt.html
Good luck man. Hopefully everything goes well and your pockets get fat with cash.