click to enlarge Failing a drug test is something no one wants to do. This is especially true when the test is a spur-of-the-moment mouth swab test. People who fail the test are usually scared they will be fired, and they expect to be called to the boss’ office. If there’s a chance you can get called on for a mouth swab test, don’t worry. It’s possible to pass these drug tests, even if you’ve done or smoked something recently. Below is the ultimate guide to passing a mouth swab drug test, along with two products to clear your system quickly.