When you take a bong rip you can't finish, leave some stale smoke in the chimney, and clear the bong by blowing into the downstem.
After taking a massive bong rip I couldn't finish, I had to "Thomas the Train" it.
This mission is quite easy if you are attentive
CJ: *loses those mfs*
Big smoke: All you had to do is follow the damn train, CJ