Never really failed to work... I seem to get asked most times I walk down the street, even if I'm suited up for work. No idea what I exude, but it clearly belies my dope intake.

I had a vaguely persistent one that got a result the other day though... kid pulls up in a pretty nice black BMW in an area normally crawling with street sellers peddling low quality hash - "Ey bro, do you smoke weed?"

"Nah man, you're good... thanks anyway" *keeps walking*

"Are you sure? We do 24 hour delivery; high grade only."

*turns back*