It will most likely be out of his system by then if he only smoked once. I've passed in less time than that, but weight really matters and Im very skinny. Tell him to exercise when possible, eat low fat foods, and drink lots of cranberry juice. Dont exercise the last 2 days before the test. When I say out of his system, I mean that it will not be detectable in a test, not that its technically out of his system. This confusion is why some people think you will fail a test unless you have a month to get clean, which is not true at all and shows they have never smoked or taken a test. If there's doubt tell him to get synthetic urine, you can find them at your local head shops most likely, call around. He can just go into the bathroom with the bottle and squirt it in the cup, perfectly legal. It stays at body temperature with a warmer pad. I've had 22 jobs and there's never been 2 weeks in a row in which I have not smoked, so you can imagine how many drug tests I've taken. The people who say 30 days are wrong, and I explained earlier why they are confused. I don't know how they explain all of us, people like me, who have smoked within a week of taking a test and passed. Detox drinks dont work, only for some people, because it wasnt the detox drink that made them pass, it was their own metabolism, but they give credit to the detox drink, not knowing the truth. Check the ingredients on any detox drink, its basically just colored water with creatine (creatine adds to water retention, so the people who have passed only passed because they diluted the test, which is the same as drinking lots of water and p****g out nothing but water, many labs will make you retest if this happens. Its happened to me before, called me back and made me retest,1 made me wait in the lobby until I had to go again, wouldnt let me retest another day). This is the most popular video on youtube when it comes to drug testing, and as you can see from many people's comments, the advice has worked for them.
I've taken at least 11 tests in the past 8 years. I've worked for Google, Cisco, USPS, a Law Firm, and Subway for examples. The longest I have gone without smoking is 5 days. I have a prescription now.