I think HoT stack cycling is going to be one of the more efficient ways of dealing with the garrote. It's what, 1000 damage every 3 seconds? Having 2 healers throwing HoT's on garrote victims should be enough, and one dedicated tank healer, or 2 if you have 4 healers in the raid. Moroes does not hit particularly hard.
I will say one thing though, for our experience with Moroes. It appeared that he targetted me for garotte about 4 times, and none of them stuck. I neglected to check my combat log to see why that was though, and after the fight, it had been pushed off due to the spam from killing the last 2 adds.