clay bath and DMPS

Our daughter is 9 and she's autistic. Her DAN doctor prescribed DMPS. We haven't used this, yet. She was chelated using DMSA 3 years ago with little results. Her tests still show high aluminum, copper, arsenic. Her serum copper levels are refusing to go down even though we have supplemented her with 75mg. zinc for a year. Her aluminum levels are off the charts even though we have completely changed cookware, water and foods. I'm interested in the clay baths. Can they be used for children? What kind is the best? Can they be used with the DMPS treatment?
Thank you so much,
Shari Tweet