The reason you develop goiter (thyroid swelling) is because your thyroid expands to trap every little bit of Iodine from the bloodstream. Goiter is an efficient tho unwanted compensation mechanism for Iodine deficiency.
Once the Iodine gets into your tissues the thyroid no longer needs this big apparatus to trap iodine. Then the thyroid normalizes in size.
But I can tell you this from people we've followed: The thyroid sometimes swells more before it shrinks. When the thyroid senses this new iodine bounty, it can't believe its good fortune and gobbles iodine. Think of squirrels gathering acorns for winter (scarcity).
Surgery is a terrible way to treat goiter and it doesn't correct the underlying problem--iodine deficiency.
If you talk to the people who have had goiter or thyroid surgery on the Yahoo thyroidless group, they will tell you what a mistake they feel they made.
Be sure to take the companion nutrients and salt water regimen or you are wasting your time and money.