Ooh, I love the FB idea!
The very best way to remove blood stains is with peroxide. Works every time and it's fast and cheap.
That's why the oxy-action stuff works, it's basically a peroxide-like formula.
Hydrogen peroxide may be cheaper, but it's not always easily available. Also, a lot of people don't know how to use it or store it. It does go "off" and loses effectiveness over time. Or if you leave the lid off, the water evaporates and leaves the peroxide behind which increases the concentration, which brings more problems. You also need to be careful about how you use it - if it is strong, it can damage your skin. I remember using it in Chemistry classes at uni to take potassium permanganate stains off my hands, and found my skin covered in white spots, damaged by the peroxide.
Marg