Well, I'm not sure that people would be weirded out -- it's not as though you'll be flinging spatter at them, willy-nilly -- but a few Neopagan traditions today do frown on the use of blood or other bodily fluids in magic. Fact is, it's a practice that's been used for a very long time. Anything that comes out of the human body is considered a strong magical link indeed -- I've used blood, semen, and urine in workings before, and it's not uncommon in folk magic at all. The important thing is that whatever you're going to do, you do it in a responsible manner. For more on the history of body fluids in magic, and why someone might use them, read on: Body Fluids in Magic.
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