Yes, I have done a type of therapy with my T called ego state therapy, in which we worked with different ego states of mine, such as versions of me at younger ages and also a "non-me" ego state too. My T is a family systems therapist, so he uses techniques he might use with a person's family with their own internal family, or ego states. I found it very helpful. We don't do too much of it anymore, but occasionally we will slip a bit in. I do not have DID. My T works with my ego states through me. I am a kind of liaison.

Readytostop, even if this type of therapy ends up not being that helpful to you, I think for anyone interested in therapy, it is pretty cool to have a go at it. If it doesn't help you, you can try something else.