AOE Tanking with Blood

Hey there, i need a little advice on how to Aoe Tank.
ATM, my normal AOE rotation is DnD>Icy touch>Plague Strike>Pestilence>Blood Tap>Blood Boil, this is fine and normally i dont lose any aggro with this.
The problem is when i need to AOE tank and my DnD or Blood Tap is on CD. What do you guys do in that situation? (This is mostly an issiue in HC Dungeons)

spam IT x1 on every mob and keep dot's on them

If you spec into the Unholy talent Morbidity, you're certain to have DnD up for every trash pull.