Zeolite and DMSA are not at all the same. I have used zeolite in conjunction with Colloidal Silver because it helps my gut issues but I'm pretty sure Cutler doesn't recommend it. I don't know if you're heavily toxic but 75th percentile sounds like a clue. As for knowing if it's all out, I don't know the answer to that either. But, I would use your health status as a gauge to your progress. If you've been at something for a very, very long time and not getting better you might need to broaden your scope.
Do I feel better? No. But, I'm dealing with infections on top of heavy metal toxicity. Finding the answers takes a lot of time.
One thing I have learned through all of this: The best way to go fast is to go slow.