This obviously works best with a KEI - If it's not your day and there's really no group to be had anywhere (and PoJ is starting to suck), head to the Plane of Disease...to the flies.
Summon pet, set up as usual, regen yourself if you can - and pull away, most can be single pulled from the right angle.
There's no secret really, probably best to pet cleric - each dead fly is approx 2% AA exp (compared favourably to PoJ), with KEI you can keep it going for quite a while potentially, just make sure to sit close to the "water" so that when the flies turn to flee they don't wander in the direction of the rats/goos. :P