I sometimes see emos when I’m riding the Metro. They’re always moping in their seats, with their heads slumped against the window, and when they get up, there’s the most hellacious, drippy greaseprint left on the window.

So Ima guess that emo oil comes from emos. You probably just start punching emos in the face repeatedly, then sop up whatever is left. You’d have to refine it to get rid of the tears, though.