I worked for an Arcade company. I was responsible for 12 locations that had approx 100 machines each. These machines generated approx 10grand a day in quarters (each location). So we all had to take drug tests each month, as well as polygraph tests.
One thing I learned from the start. If you smoke a joint BEFORE a polygraph you are the worlds most honest person. THC equalizes your metabolism, and makes even a LIAR appear truthful. Bottom line is every month I would pee positive for weed, and the polygraph would exonerate me. EVERY MONTH! I worked there for 6 years right out of collage.
What did I learn? Get high! It makes you a truthful person. (on paper)
Even tho I am a fun loving guy (hippie things) I won't have a "high" guy work for me. If the customer wants to hang out, and get hi fine... Not me or the guys that work for me. EVER! There is ONE excuse for poor workmanship. Inexperience.