Debate? Hardly. I have had cleaner wrasse and cleaner shrimp clean my teeth many times (in my 3000 plus dives) and I am reasonably sure I do not have ich which in marine fish is under the skin and not available for consumption. Also, if you use Google Scholar you can find the assays of the stomach contents of cleaner wrasse and cleaner shrimp in various marine biology papers and it does not include marine ich. But if you believe its true, good luck.