Re:

Hah. Some even claim it's a "chemical".

Iodine is an element, like gold, silver, sodium, potassium, magnesium, etc.

Those who would believe that Iodine is a chemical, should also argue against magnesium, calcium and all the elements that are essential for life. How loony would that proposition be ???? But its the same as arguing that Iodine is a chemical.

People choose to get Iodine however they want - iodized salt is one extremely dilute way. Kelp is another way.
Lugol's solution is another. With Lugol's solution, it is a concentrate, that is convenient because a small amount of the solution has a lot of iodine and it can be diluted. It's like buying orange juice concentrate that you later dilute before drinking it. You could equally use freshly-squeezed and skip the dilution.

Everything's got chemicals, even the brain - serotonin being one "chemical". Herbs contain chemicals too, some of them are insidious kidney toxins that you don't learn about until its too late. So, arguing against materials alleged to be chemicals when they're not, and turning around and promoting herbs that themselves contain chemicals, seems odd.