I've been in need of a job for a while and I finally found a good one, the only problem is that the day I go in for the interview they will test me with an oral swab test. I smoke about twice a day, and i'm about 5'6 160lbs. I can go in for the interview whenever I want. How long should I go without smoking before the interview? Should I do anything else? (drink water or cranberry juice) to ensure a clean result?