I know this might sound disgusting but my brother "collects" booger from his nose and smears it all over his bedroom wall. I'm not sure how to describe the smell, so the closest I can think of is China Town's fish market. He is delusional and believes that it will become a famous piece of art one day. This obviously won't happen so I need some suggestions on how to clean his wall while he's out with his friends. Should I paint over the walls? I do not want to scrape the dried and crusty boogers off the walls because it will create "booger dust" and I might get some kind of disease from it.

Desperate help needed quickly!