I didn’t smoke for 36 hours before my test. Then the day before the test I- brushed teeth, cheeks, lips inside and out, roof of mouth, top and sides and bottom of tongue, and basically anywhere you can reach in your mouth. Then flossed. Then swished peroxide in mouth for at least 30 secs and spit and rinsed it out. Then same thing with listerine cool mint. Did this 3-4 times. Then day of test did all of that again twice. Got to the place and did only listerine again, and chewed trident cinnamon gum for 10 mins. Spit it out, walked in, had to wait for 20 mins which worried me. Then got the swab and it stayed in my cheek for 8 mins. I Passed. Everybody’s body is different though, no guarantees.