This sounds weird but I swear it DOES work! I learned it from my medical assisting teacher when I was in school. YOUR own saliva will get out YOUR own blood. (my own saliva will get out my own blood, etc) There is an enzyme in saliva that breaks down blood. But the key is its got to be your saliva for your blood so basically just spit on the blood spot! :0) It will work!
You could use hydrogen peroxide or club soda. Use only cold water. Soak, then agitate, then rinse. Repeat this until it's gone. I usually use hydrogen peroxide on garments that have color to them when i get blood on it accidentally when i have a period and it doesn't remove the color.
Wet blood? Hold the item under running cold water, rubbing gently--keep going with the water and the rubbing. Dried blood? The peroxide is good. So is OxyClean: wet the stain, rub on some OxyClean then gently rub the the fabric together;add some cold water, etc.,etc., until stain is gone.