Update, I got it done just a couple of days later and now it's fairly easy to do for me. Usually takes 3-4 mins. and I complete it in blood spec. wearing DPS gear.
I did it as frost, though I did have to switch to DS for a bit. Key thing is to, one, keep diseases up, two, use KM's on oblit, 3, stay against the wall, and four, switch targets with a macro every time they swap or you lose out.