Hi there
Let me begin by saying I have no tact so my understanding of revenge is different from how a T would verbalise it.
I understand this disorder and the cause and the effect like a dog with a tail. There is no cut the tail off option. So I as a dog, have to learn to sit in a way so that I don't hurt myself if I sit on my tail. As much as I would wish to I cannot cut off my past. It will always follow me. I am not so altruistic that I don't wish the wheels of karma to hurry up and run over my abusers. I am not so mature that revenge has never crossed my mind. And for me the best revenge isn't having a great life because my abusers aren't around to see me living it up. Time, death and geography have separated us. I don't even know if they're still alive.
I have written countless letters, and it is true, it does help to purge the blackness from the soul and at least help those inside who battle to cope with hurt and pain a chance to express themselves. Something else I did, but only on paper and only in therapy was to play out a hypothetical revenge. What if this happened? How would #3 feel? How would #4 feel? The outsiders wrote their answers expressing their emotions down.
One cannot go around drowning in a sea of emotions all undealt with, some emotions can become toxic to you and to some alters. You cannot become adrift in a desert feeling nothing either, that comes from suppression, as the poster above said, to cry was cathartic.
Anyway you develop to explore and understand your feelings and emotions is a good way. Whether you take to meditation, or shouting on top of a hill, keeping a daily or even hourly diary, writing letters, painting (you don't have to be Rembrandt the point is to use colour to reflect emotion), play with clay, pop art, computer art. There are many outlets for you to express your emotions - revenge is an emotion. So find a bunch of violent images, hell, one daily paper is enough of a resource; do it on computer or on paper, let the alters who need to speak write or type words over the images and when you're done print it and put it in your diary or journal.
Y'all have a nice day now.

#1