The bluing agent is the eye-of-newt for us old alchemists :P
I should dive into the modern world and try a new oxi-product!
I will report back after a proper investigation! If your input is as good as you all claim, I will publish the findings in suitable journal (nothing < IF 10!) --I'm sure it should be fairly straightforward to elucidate the mechanism.
Just made me laugh as I had not heard og blueing washing since the middle of last Century- doesn't mean it's a bad idea. I use Fuller's Earth all the time to remove grease stain- fabulous product, totally respectful of the environment (it's a natural clay powder- called Terre Somières in French- which I buy from my druggist) and of the materials. Put a thin layer on the grease stained area- and leave overnight- brush and wash - it will wick off the fatty stain perfectly. Love it.