I'm trying to understand how the free floating heavy metals, from Iodine detox, are really eliminated from the body. I sort of understand how chlorella and cilantro do it by binding to the metal and then evacuate through normal body processes.

I use this clay, called pyrophyllite, for extra trace minerals and detox. It is better than bentonite; because it is a non-clumping clay. So, it won't cause bowel movement problems. So the flyer says this:

How does Sacred Healing Clay both nourish the body and pull out heavy
metals at the same time?

The clay will naturally remove heavy metals as it adds beneficial minerals back into the body as nourishment due to the process of compounding. Heavy metals are converted into silicates and other harmless or even beneficial compounds when clay is added to the diet.
All metals are either supported or counteracted by other minerals. When full spectrum mineral sources (like clay, Sea Salt , seaweeds, horsetail, nettles, alfalfa, etc.) are added to the body, an abundance of counterbalancing minerals become available to the body for compounding. The counterbalancing minerals bond with the isolated heavy metals, converting them into compounds, and making them either unavailable to the body or beneficial to the body.
A common example of this compounding process is found in the combination of heavy aluminum with silicon (a mineral). The compound is called “aluminosilicate” and is one of the most beneficial compounds for agriculture (and happens to be one of the most abundant of all mineral compounds found in nature).
Aluminosilicate is harmless to the human body, and actually holds one of the secrets to removing heavy aluminum from the body.

Now it sorta, kinda make sense.

This clay has been very good for me. I haven't used the loose powdery clay; because it won't clump and is difficult for me to apply to my body. I used the capsules for internal use. If you're interested
http://www.pyroclay.com/
.

Also, off topic (sorry), I found this paragraph interesting regarding how bad vegetable capsules are. This is from the same pyroclay flyer.

The capsules we use are gelatin caps, not vegetable capsules. (We discovered at great expense to our health that most all vegetable capsules are actually toxic to the human body and are difficult to digest.
This is particularly true for those who take a lot of capsules. The resins they are made with generally all come from pine tree resin (hard on the kidneys) or an extract of corn (from where?). One source even had sorbitol in their blend, a common food additive, with numerous digestive complaints as side effects.
For this reason, we no longer use vegetable capsules. Gelatin is actually a long-standing Chinese remedy for digestive disturbances and other health conditions.)