When I used Miracle-Mineral-Supplement (type 1 diabetic here, had it come in after amalgams) I had higher bloodsugars on max 4 drops/day.
The dieoff symptoms were a bit hard too. I have the feeling the problem was that I wasn't getting enough alkiline minerals and antioxidants to help clear the load.
Type 1 D and the hypothyroidism both have roots in persistent infections that keep the body's glutathione resources busy. (Glutathione is the major antioxidant molecule produced in the body)
Cleansing definitely helps, so you can of course try the Miracle-Mineral-Supplement . His experiences may vary from mine, since each individual is (*gasp*) quite individual.
1 drop Miracle-Mineral-Supplement to 1/2 liter (2 cups) distilled water, for the whole day, could be a good place to start. I'd say watch for blood Sugar changes. If there's issues, a nap and an Epsom Salt foot soak should help. :-)
Has he tried freeze-dried thyroid as opposed to the synthetic hormones? It's been making a subtle but nice change for me, but he's in a different basket, with the surgical removal of the thyroid. I went to an orthomolecular (vitamin-trained doctor) for instructions and a perscription.