Re: smoking in public?
I smoked outside the laundromat tonight. I recommend keeping the shisha box with you, just as a backup. If the police give you any trouble, just be nice and calm, and offer to stay there until they can get a field test kit. If you are compliant and respectful, they will probably accept what you have to say and not bother with testing it. Besides, law enforcement knows what illegal substances look like, and what tobacco looks like. Just don't be a douche, and you won't have problems.
exp: military police, and private security officer
Live, learn, love hookah.