Dehydrating my own urine

New to the forum, but used the Dilution Method, Tips and Tricks to pass a UA for employment last week. Thank you Cannabis.com!
I'd like to post my success story for the benefit of all, but first, I have a question:
I have been clean over three weeks now and was a moderate smoker prior. Now that my urine is clean, I would like to dehydrate some in the unlikely event that there is a random given at work.
Can anyone give me a method or direct me to a site that has this info?
I'm ready to roll one, but would like to save some clean urine first!!