How do I get it off my face? Its disgusting.

You can opt-out of being harvested here. It was broken though, and I'm not 100% sure it's been fixed.

I had harvesting disabled but the snot just won't go away. Is it supposed to disappear on its own? I already got the achievement so I don't need to get mauled any further but still, snot's gross.

Yeah it's supposed to go away when you opt out. It might still be broken then; I have a coverup on so I can't see when or if my HA resets to begin with so :x

Argh. Guess I'll just leave it for now. I hope it goes away soon. Thank you for the info :)