It's the therapist's job to know with whom and when to do EMDR, not the client, though I'm glad when readers get their eyes opened that some practitioners don't know about dissociation.

Yeah, alters thinking the abuse is still happening (when it isn't anymore) is a thorny problem. I always do these things with my clients:

- I ask each alter/ego state if they know what year it is and where we are
- I ask them whether they know they are in the same body -- I keep a mirror handy to "look through the eyes," and ask them to look through the eyes at the body, the clothes, the jewelry, and ask, "whose hands are those? whose face is that? whose clothes and body?"
- because this is shocking or confusing to parts, I quickly back off and say, "don't take my work for it, I could be wrong. But if I'm right, and you are in the body with her (or him), then there are alot of implications, aren't there?"
- Then I concretely spell out the implications as I would to a child, because alters use trance logic and are developmentally young. so I say, "when you make her cut, if you are in the body with her, isn't it YOUR body you are cutting?" and other implication.
-Then I say, you don't have to decide today, but I'm happy if you just CONSIDER the possibility that things have changed, that it is 2007, we are in (town's name), that you are in the body with (client's name).
- I always finish with, "Thanks so much for what you do." because no matter what they do, EVEN IF THEY ARE PERP INTROJECTS, they serve to help survival in some way.

I don't know if any of this applies to your case or any other specific case, but in general, repeating these orienting responses and appreciating parts goes along way to changing internal dynamics as a starting point.

There is more to it by a long shot, but .....