I think it is just the luck of the draw at how fast it is found. I was at a lower level (60s?) when I got these three quests. I was prepared for it to take forever, but boom, they all dropped within a half hour and I used no tricks. This was LONG before the ability to summon phenoms, etc. I was amazed and felt guilty because so many of my friends , including Admin, had been and still were struggling with these quests.
I was happy yo have found it and be able to move on, but I know many who still struggle. The thread with hints on how to set up finding them has been a great help to many, but others still have had no luck...... So I go back to luck of the draw. I wonder if the new update will change how this quest is resolved and those oil cans so many of us struggled with!