This quest is part of the Something for Everyone, required for the Meta The Party Herald. You'll see it on your map in Revendreth, once you hit Honored with the Ember Court.
Filling the canister is really easy as for the [object=355971] that's another story, either if you're low or high ilevel is very much recommendable to do it in group and the whole area is covered with Elites.
Here you have the whole compiled list of them, really easy to use with Toolkit on extend macro because they do not respawn once you take them.
/way 26.6 20.8
/way 27.6 23
/way 27.7 21.5
/way 28.2 25
/way 28.21, 24.92
/way 28.3 24.1
/way 28.9 27.2
/way 29.3 29.4
/way 29.3 29.5
/way 29.5 29
/way 29.57, 27.30
/way 29.73, 25.85
/way 29.7 27.3
/way 29.8 22.4
/way 29.8 22.5
/way 29.8 25.9
/way 30.18, 24.58
/way 30.3 30
/way 30.6 24.7
/way 30.7 18.8
/way 31.3 24.4
/way 31.5 24.5
/way 31.8 15.1
/way 32.8 27.2
/way 33.1 17.8
/way 33.8 24.9
/way 33.8 26.4
/way 33.8 28.3
/way 33.9 26.5
/way 34.8 24.2
Thanks to Kmccorqu and Tenko for compiling the points