Adding a comment here since I finally found a competent 5 and completed this quest after having it on the log for months--Yes, just keep turning left and the store is in that dead end.

No, you cannot complete this in raid, as with almost all other quests as of recent patches.

The dead end is naturally filled with mobs, and we found the Undead Courier there as well to kill him for the postbox keys. When you approach, the Great Fras Siabi himself shows up looking pretty ripe, and of course if you haven't cleared the area carefully and thoroughly first, you're in a position to get owned, which we almost did. Also don't screw around with the postbox until you're ready, as that spawns 3 elites too. After Fras is put down, everybody can loot the tobacco box for the win.

The Lighter isn't all that--with the exception of the fact that it doesn't get you drunk, it's graphically and effect-similar to Thunderbrew's Boot Flask. Yet another novelty trinket taking up space in the bank.

If you're 5-manning Scarlet Strath, you might as well do this one as the dead end isn't very much additional work once you've cleared the street to that point anyway. It's not in itself a reason to do Scarlet Strath in 5, as the quest ends there and doesn't follow on to my knowledge. This, Flesh Does Not Lie, and Restless Souls are all pretty easy to complete in the first half-hour of the instance (Flesh is a drop quest so your mileage may vary).

IMPORTANT:
The above text sort of obscures this very important point for people who skim.

Fighting Siabi will cause any loose undead in the vicinity to come to his aid. I found this out the hard way.

This quest is named after Lead Quest Designer Alex Afrasiabi, if anyone was wondering.

As u enter Strat Scarlet u must kill every mob up until the tobacco. to get to the tobacco u turn left then left again and its to the right of the well thing. But plz ensure u have killed all the mobs on the way to the tobacco. Once u have opened the box a guy will spawn and u kill him, he is lvl 61/62 elite an he drops the tobacco..........hope this help :)