13 Aug 2012 13 Aug 2012
Here's how I got the Achievement; I'm sure there are other places you can get it too.
Head to the Sorrowing Meadow (graveyard) and visit the first of the four mansions for Cora. Now you'll have the wall jump and the choice of which mansion to visit next. Pick the Southeast one and make your way there. When you're two rooms north of the mansion entrance, you're in position.
Enter the room from the top - you'll see climbable walls on both sides, and to the left, a path with some spikes and a bug nest. Run past the bug nest and you'll encounter several zombies and a giant insect on the ground. Run just past them without fighting, and stop on the ledge while you wait for the enemies to approach.
Select Fidget's Lightning attack and start shocking the enemies who are following from the right. Once few if any remain, drop down and continue using lightning attacks on the many zombies below. Keep the shock going as long as you can, switching to melee attacks when Dust gets too red. Repeat this without missing or getting hit and you'll hit 1,000 before the room is cleared.
If you mess up, just exit from the top and start the process again. Also, if somehow you're killing everyone before you get 10K hits (which was not a problem for me), remove the augment you have equipped in order to reduce your attack power.