I'm sorry, but does the therapist know you are having your daughter bite down on soap? I know some people think that is perfectly acceptable form of punishment. It just seems really archaic and demeaning, and it sounds like it escalated her anger. I just can't imagine a therapist condoning that. I'd be interested to know if therapist instructed you to do this and what the therapists justification for it is.

This must be incredibly frustrating for you and stressful on the entire family. I hope others have some ideas to help your daughter and your family.