I can't see anything wrong with this - any form of substance use which affects safety, regardless of whether it's legal or not, is totally unacceptable in anybody from the captain to the ground crew's tea-boy.
And also it's worth looking at it this way. If after any initial campaign no problem is found, the powers that be will divert their scarce resources elsewhere and leave us alone. If they do find a problem, it can be dealt with.
G