best place to grind AA where mobs don't run away

[Praxxis]

I've been trying to find a decent spot where mobs don't run away, but my tier 5 merc tank + my warder can slaughter and don't have to worry too much about mobs running away and bringing friends back :)

So far, Katta elementals have been the only spot I've found for this.  Any other suggestions?

P.S.
Before someone says it...I would like to do this without using Hobble AA.  If you wish to know why, PM me.

[wildwaters]

with 2 mercs you must have abox so 4 = katta instance. I blow through those pretty fast now when I want a place to hide while Pling friends. No compettiion and easy pulls.

Maybe kaesora or an instanced FOS themed mission.

I can't actually remember if half the places I am thinking of run or not cause  have hobble and it works well.