Let’s see how you feel once that dog maims or kills someone. Especially if no one is sitting there with a 9 mm ready for it.
The question does not need to be answered, because it does flush out of their system. If they show up to work with alcohol in their system, or they have an accident with alcohol in their system, they are fired, prosecuted, and hopefully jail. Pot is entirely different. It is still illegal federally. No company in their right mind would hire a pot user and put them in a situation that could hurt or injure someone. A pot user lying about it, hopefully will be caught with the drug test.
About as likely as your wife cutting your testicles off. How will YOU feel about that?