MasterShake420

Hey, there wasn't a forum for this so i figured id put it in here and the mods can move it as they wish, but how do they do teeth testing? When i got a job at Kroger, before i smoked, i had to take a drug test and they gave me a thing that looked like the top half of a tooth brush and i had to rub my gums with it and keep it between my gums and my lip for like a minute and then they sent it off to some place and said i was clean. I was just wondering how do u pass a test liek that because ive started smoking again and im going back to work there (i quit when i started smoking) and ill have to take the test again. Thanks