pepperidge, attachment therapy for us didn't entail holding, rebirthing or any of that stuff (I believe it's now illegal in most states) nor has it ever. I never saw the need to completely break a child's spirit in that nature AND it doesn't help a child to "trust" an adult caregiver in my humble opinion.
We started out small ~ nurturing things. Games that included kt & wm having to make eye contact & listen to husband & myself. Mother, May I immediately comes to mind. husband & I were taught to "reparent". So I did a great deal of rocking allowing kt (wm was too cool) to drink from a bottle or use a nook. Essentially husband & I were filling in gaps that were missed from birth to 6 years of age.
Spent many therapy sessions on calming & then teaching self calming; used a great deal of parts language. Much of the therapy included puppets, dolls, etc that changed from one thing to another. A tadpole into a frog, an egg into chicks (really cute toys), yet that toy was one in the same ~ basically teaching the tweedles a sense of self. Many attachment disordered children have no little or no sense.
It all came down to nurturing & teaching the tweedles to give up their need to self parent. I'll be honest we still do attachment/adoption/trauma based therapy with kt & wm.
It's a long arduous journey & it's hit or miss. Sometimes the disorder is far too ingrained & a difficult child cannot let go of his/her need to self parent. They never learn to trust an adult caregiver. (wm is pretty much in this spot).
I've given you some ideas & yet have kept it as general as possible to protect my twins. I hope this helps. If you have any specific questions feel free to PM me.