The only thing that I have found to work is cowboy magic detangle and shine. It works great, detangles instanstly leaving hair really soft and it won't leave their hair greasy at all. You can get it at a horse place I got mine at petsmart the one that has horse items, it is in the horse section. It was intended for horses and humans and works great on yorkies, other members use it as well and they all love it, and it is not expensive at all.
The ice on ice CC product works good at first but as you continue to use it, it tends to dry out the hair.