I searched and didn't find anything on the subject, so here ya go.
As an Engineer, you have the ability to make a plethora of Target Dummies. While practically useless, they have a unique trigger that lets you 'land' the killing blow after so many seconds.
After the Dummy fails, he explodes; therefore giving you a killing blow and proccing Spirit Tap!
I don't know if this is available @ level 80 considering there are no target dummies with their ilvl high enough to fall under the 'experience or honorable kill' level restriction...but at least it could be a helpful grinidng / twink option. Thanks!