One of my concerns about using MMS is the effect this supplement could have on thyroid function and the endocrine system as a whole. Here's a old post about this:
MMS-miracle mineral supplement (permalink 130)
There's a lot of good discussion on Carla's MMS thread and as usual not all of us agree about its use. I think discussions which encourage all to participate and make their own decisions about what has been discussed it a good place for a forum to be.
Anyway, I agree with Kat, this is one supplement I would not try. After all I have a whole house filter to remove chlorine from my water so I am not going to add chlorine dioxide as a supplement. I feel many with Morgellons could be borderline low as far as optimal endocrine system function.