My guild had two replacement healers in yesterdays kara run. Im 40/21 Demo/dest. We had some doubts about only two 'new' healers on such a healer intensive fight. I made the choice so give up some dps to help them out on cleanses.
I dismissed my succy and summoned a fel hunter. It worked out really really well. He was able to get the cleanses off without a problem, only once did I see two inbetween the cooldown. Since he was independent of my global cooldown, I was able to get them damn fast. Most times, before the healers saw it.
I was pretty surprised how well he stayed alive. Eating the buffs kept him healed up for the most part. He was even able to move and gain LoS to get the cleanse. I kept him to my side, figured that AoE would kill him fast.
Strange thing was, I was still top dps lol. Good times.