Oral tests are very inaccurate and the false positive rate is huge (can be more that 50% for some manufacturers, you're better off flipping a coin). To my best

Oral tests are very inaccurate and the false positive rate is huge (can be more that 50% for some manufacturers, you're better off flipping a coin). To my best knowledge, oral tests are usually confirmed with urine and/or blood samples (at least that's the procedure if you test positive while driving here). So as far as I know, there isn't a reliable and accurate way of testing.