I don't think Cutler believes those claims about MCP. He does not seem to think it is unsafe to take. A few years ago there was a discussion on the subject in one of the yahoo groups. I don't know about alginate.
Actually he does not think any of the chelators in his protocol bind irreversibly in the body. That is why we need to take doses frequently and take generous doses of antioxidants. They are just the best we have.