Breathalyser
What's the cost of a relyable breathalyser?
Having one aboard could IMHO be an appropriate tool to avoid lots of trouble.
On any suspicion, be it from fellow crew members or third parties, once could be able to perform a 'self-test' to convince either oneself of a 'no - go' or relieve others of their concern of someone having had too much to drink before reporting for duty. Thus avoiding ruined carreers, possible jail sentences and above all maintaining the highest safety standards.
It might also come in handy to face potential troublemaking passengers if cabin crew believe said passenger is under influence. A discrete breathtest is at the least a strong and indisputable argument in the process of telling someone to behave and be good for the rest of the flight, explaining the possible consequences.
A small price to pay, for safety?
Rgds,
BC