Whether it blows up or not depends on your timing, you cleanse it too early and those that got sucked in but not rooted take dmg, you cleanse it too late and the rooted one blows up. Usually it's best to wait a sec or two before you cleanse, so ppl can get away, but in pug groups some ppl just stand there. Either way it shoudn't be a problem to heal through, at least if the vortex isn't in the area with the flaming oil and you have exploding mouse droids on top of it. ;-)