I'm so sorry that you are having to deal with this.
It looks like @Eggcessive and @chickengeorgeto have given you some good advice on the other threads.
I was asking all the questions, trying to determine if they had gotten into some bad food or if it was some other type of illness running through the flock.
Unfortunately it is sounding like mareks.
@Eggcessive gave you some links on the other thread : http://www.backyardchickens.com/t/1072967/chickens-dropping-like-flies
If you have some that are still well, I would try to separate them from the sick ones if you can.
As far a supportive care, I believe courses of treatment and care are in the links given to you.
I am glad the one that you gave a bath to is standing up more and eating/drinking.
Just wondering why you might think they were poisoned. Were you thinking someone harmed them or do you think they got into something like rodent poison. If that were the case I think they all would be showing about the same symptoms at the same stages, where as with illness, it can have different stages depending on the age and health of the bird at the time it was contracted.
Please keep us posted. I really wish I knew more.