Question regarding Mind Control in PvP

[Hellojello]

I tried asking in World but I wasn't getting serious responses, first time as a Priest so I'm unsure.

Back in TBC or WotLK when I PvPed in Orgrimmar Horde Priests would MC me occasionally to heal and buff me up. I'm trying to return the favor to lowbies I run into, however, I'm not getting much cooperation from them. (Skull Horde everywhere)

Can I do this on Nost? What I mean is MC > Heal > Buff my controlled target. Thanks guys!

[Ana]

If you try to cast some spell while MCing someone, bad things happen. Best get another person to handle the buffing while you keep the MC up.

[Brion]

Once you start casting a spell, the MC breaks. You can get instant cast spells off (PW:Shield, Fort, Renew) before they turn hostile again.

[Hellojello]

Thanks for the replys! Found an afk player on Horde to test things out... Heals definitely didn't work, but instants like fort and shield didn't either, my character got stuck casting after canceling MC and could only be cured by pressing ESC.

Someone suggested making them my focus, but I'm not aware of how to get that working yet.