AoW is basically always up. I'd say every 3-4 seconds on average. It's a lot of throughput for healing but hard to manage with everything else that's going on.

What I've got for CC macros are these two:

/castsequence reset=combat/8 [target=arenatarget1] Repentance,,,
/castsequence reset=combat/8 [target=arenatarget2] ,Repentance,,
/castsequence reset=combat/8 [target=arenatarget3] ,,Repentance,
/castsequence reset=combat/8 [target=arenatarget4] ,,,Repentance

/castsequence reset=combat/8 [target=arenatarget1] Hammer of Justice,,,
/castsequence reset=combat/8 [target=arenatarget2] ,Hammer of Justice,,
/castsequence reset=combat/8 [target=arenatarget3] ,,Hammer of Justice,
/castsequence reset=combat/8 [target=arenatarget4] ,,,Hammer of Justice

Of course each toon's macros start with a different amount of commas so that it goes in sequence. What this does is make it so I can spam the button and they'll all just cycle through. My cleanse is setup the same way and it works very well.