If you have a good excuse, use it. Even if only to delay the test. Delay it as long as you can. Then, when you do take it, either go to GNC and buy the cleaning shit. It cant hurt. Get a friend to piss for you in a camera film bottle and put it in your underwear. I took a test once in college and used the piss in the film bottle plan. I drank a shitload of water before hand, so that I would have time to "work", then while I was taking the longest piss ever, I pissed on the side of the cup they gave me to make the right sound because the guy was standing about 8 feet behind me, and poured the clean piss in the cup, stuck the bottle back into my boxer briefs (just under my sack), and finished up. I washed the outside of the cup at the sink before I gave it to the NCAA guy. He just thought I was a sloppy pisser. I actually practived making the switch about 5 times before taking the test.