Hot water or putting something with blood on it in a dryer will set the stain and make it near impossible to remove. I use an enzyme cleaner, like the kind for pet odors and it works pretty well. Never tried hydrogen peroxide. Whatever you use, make sure it is applied when the stain is fresh for better results.
What happened to vlemmy.net? I’m OOTL, all I know is I can’t login or reach the server.