I'm nooo Iodine expert, this is just my personal experience on iodine.
When I started iodine, I did go through a good week or two of feeling like I had a bad flu. Lots of mucus, throat was a little sore, swallowing was hard, headache, body aches, etc... Since lots of people on here recommend pulse dosing for detox, I gave that a try, but in the end, it didn't work for me. I then went back to taking Iodine every day and added an extra salt loading. So now I was salt loading 2x a day. The extra salt loading did help me a little, but what really did the trick was when I decided to continuing to increase my dose. With increasing, the flu thing passed quickly. Then, later on, on a higher dose, I had another detox. This time my face and body broke out in a horrible rash/ Acne (bromide acne?), so I again dramatically increased my dose. I was taking 120mg at the time and jumped straight to 150mg. The rash/ Acne started to go away after I did that. I still have some of the acne/rash but it's like 80-90% better at this point
For ME, increasing my Iodine dose helped with my detox symptoms
**Also want to mention I take all suggested co supplements. Selenium, mag, niacin, vit c, etc...