Quick skim of Pub Med says no signs of toxicity under 400 ppm and 98.2% efficiency against bacteria and fungi.
But also this: used for disinfecting medical equipment, not safe to ingest. Will not cure any disease.
https://www.chemicalsafetyfacts.org/chlorine-dioxide/
I cant find anything reputable about the red cross using it, but the wikipedia description says "MMS is falsely promoted to cure HIV, malaria, hepatitis, autism..."
If you look at how ClO2 works chemically it is literally like drinking bleach. But Clorox is also great for killing bacteria...
None of what you found is true. Don't you realize there are trillion of dollars at risk if the truth was known by everyone.