Dr. Brownstein recommends titrating up to 50mg a day of iodoral capsules or Lugols Iodine with the required co-supplements listed in the above link.
Most of the iodine painted on the skin evaporates and only 12% is absorbed by the body. The seweed capsules also contain contaminants from the ocean, and iodine content is not reliable because iodine evaporates from the seaweed when it is processed.
The best reliable sources for iodine are Lugols and Iodoral.