H2O2 and blood stains
I believe oxygen acts as a bleach for many pigments, yes? And I
believe hydrogen peroxide reacts with hemoglobin resulting in rapid
degradation into H20 and O2, i.e., liberating free oxygen.
The rule I was taught about temperature didn't have to do with
washing, but with soaking--soak the stain in cold water, then wash it
however you normally would.
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