I can just tell you my very recent experience, and that was for a job with a law enforcement agency that I needed very badly. I tried a synthetic urine which had to be heated in the microwave before leaving home for the test, then have a hot pak rubber-banded to the small plastic bottle and hidden in my sock until I went in the bathroom at the office. The small bottle had a thermometer strip attached to the side; sample must be between 90.0-100.0F. I went into the bathroom, poured it in the cup, saving a little to pour into toilet for looks, and handed it in. 72 hours later I was contacted to inquire when I would like to start my new job...if you need to pass a test, this is the only foolproof way to go...