I do not find european stuff to be any better......especially persil, it is not even the best sold over here...first comes P&g dash...
I do not understand why there is a such a thing for this persil, there are much better products around and of which countless american ones.
Henkel persil powder DO CONTAIN bleach. Oxygen bleaching agents, persil it is actually universal and can be used for colors and darks, even though for best results they reccomend the color version....but there is no label stating you cannot wash colors or darks with it and you actually can, did that all the times, and so does the most of folks in this country where stuff for colors isn't really common, what you cannot do with it it's woolens, obviously.
For blood, either fresh or old, really I have nothng to say, for me it usually gets out just fine with an hot wash and regular "good" detergent, no prewash, no cold start, and cannot really understand how some people do have so many difficulties removing it, I do not even have problems and concerns about it getting "fixed" with an hot start, never......it gets washed out, always and really simply.
Enzymes sure helps, it's an enzymatic stain but also bleachable so oxy stuff also works.....
But again, never had problems .... So cannot give other advices than just tossing in the washer and wash...
At this point....
What I would do is soak the item in a really generous amount of detergent, you could even try making a paste with the detergent and let it sit on the stain for awhile....