IANAMD I made a quick search and the evidence of methylene blue as a carbon monoxide antidote looks controversial. IIUC part of the effect is oxidizing/reducin

IANAMD I made a quick search and the evidence of methylene blue as a carbon monoxide antidote looks controversial. IIUC part of the effect is oxidizing/reducing the iron atom in the hemoglobin, and that changes how strong is the bound with the O2, CO, NO. But my chemistry is not enough to give a good guess of the results.