SO far my runs:

1: Toxic revenger (outrolled by some paladin)
2: acidic walkers
3: acidic walkers
4: acidic walkers
5: acidic walkers
6: hydrocane
7: acidic walkers
8: acidic walkers
9: hydrocane
10: acidic walkers
11: acidic walkers
12: acidic walkers
13: acidic walkers
14: acidic walkers

I'm getting sick of this ****.

I farmed this guy for several characters and kept stats:

Acidic Walkers: 19
Hydrocane: 5
Toxic Revenger: 2

Or, if you're interested in the sequence:
Cane
Walkers x4
Cane x2
Walkers x4
Dagger
Walkers x8 !!
Cane
Walkers x2
Dagger
Walkers
Cane

Farming it with a high-level character for a low-level party member is easy.  Set group loot.  Both of you enter the main entrance of the instance (for horde, make a left when coming out of the train depot).  The low level character can stop at the big rotating warning light inside the instance ('Clockwerk Run').  The high level character jumps into the pit, trying to land on the big gear.  Pulling Viscous Fallout back against the wall below where the low level guy is standing) and loot, the low level character can roll on it.

Now the high level character can exit (south) through the dorms, clean room and then right at the hall of gears to get back out to the main instance.

You can do the trick with logging out to teleport back to the beginning, but why bother?  With the 4-instances-per-hour limit, you may as well walk back since you can easily do the first part in less than 2 minutes.