Will xanax and Valium appear within a mouth swab oral exam? If so how long does it purloin?

There is a mouth swab test to be taken and i need to know how long it is going to bear before i should take the question paper so that it is out of my system?
Answers:    Why is there any IN your system in the first place?

They are benzodiazepines, and are detectable by standard urine drug screen for several days after ingestion. I am not aware they are detectable by "mouth swab"
Most pills only stay in your system for a little. Like literally if you wanted to be completely sure maybe a couple weeks, but a couple days is much more natural. Plus its not anything technically illegal, the individual administering the test doesnt know if you are prescribed the medication. If they ask just let somebody know them they were prescribed. Wait like a week and it will be cool.