We've done if a few different ways, though we've never had much problem with it so I can't say I have given it much thought. Either a ranged dps pulls them away and kills them, or some aoe damage from me, I'm a juggernaut tank, is enough to keep them hitting me instead of the healer. They don't do much damage, unless they blow up, so we've usually burnt down the boss before it became much of a problem.
What triggers them to blow up? timer?
I've been kiting them as a Merc DPS and have them blow up away from the melee. One always seems to stay in melee and eat or group.