Some people use only ALA for chelation. Have you tried that?
I've read about people who have used IV chelation very successfully.
Cutler also hates the idea of using cilantro for chelating. I've been using it and chlorella for some months now and my health has been improving a lot.
My main point is that Cutler is a great guy and a very important person in the field of chelation therapy, but his advice isn't necessarily going to fit every person's situation. You may need to look around for alternatives (like the ALA-only route, for example).