I've Downied, steamed, and even curling-ironed (low heat), and I see no damage yet. And I really LOVE my dolls! I'd rather "doctor" them at home than send them away to the hospital.
I soak the hair in full-strength Downy for an hour, and then rinse really thoroughly with just barely lukewarm water; let the hair air-dry, gently brushing it out with an AG brush while still damp.
It should still curl under on the ends after it dries--if it doesn't, just dampen the ends and use curlers to recurl it; after it's dried it will stay curled under. [img]smile.gif[/img]
Good luck with your dollies' hair! [img]biggrin.gif[/img]