Originally Posted by
nycquilter
the enzyme that is needed to dissolve blood is contained in the saliva of the person to whom the blood belongs. So, have your son spit lots on the stain until it is wet then let it sit a bit then wash. This usually works especially if the blood is fresh. I managed to bleed on the white background of an applique piece after sticking my finger and not realizing it. No sign of the blood now after I saliva-ed it to death!
That's exactly what I have been told to do and it has worked for me too. Although it should be done soon after it happens so not sure if waiting will make a difference or not. Good luck!