So in summary, the FDA prevents you from marketing something as a medicine unless you have gone through the approval process and developed all the regulatory apparatus around a medicine (e.g. packaging, suppliers, prescription guidelines, etc)?

Yes. Look, I'm not arguing this is bad, I'm just trying to respond to the original question and capture the essence of the debate.

There are three pertinent points: (1) it's EDTA; (2) it's not that EDTA is safe or not safe, it's that no one applied to have it approved as an OTC medication; (3) you can still (probably) sell EDTA as a supplement in the US, but the FDA grumbled about it, which angered various chelation cranks.