I suppose some do. But neem oil isn't going to wash off with just water or H2o2 I don't thin k. I could be wrong because I've never had to so I really don't know.. I also was going to mention washing the weed. It may be fine. I just know that I personally wouldn't smoke anything that had neem sprayed on it six weeks into flower. But I guess it's worth a try. I'm just really picky with what I smoke. That's why I grow my own. I have a friend that was showing me his grow one day. There was a can of raid outside the grow tent. I asked if he was spraying it on his plants. He said yes. I just rolled my eyes. I tried to explain but he didn't seem to care. Another pet peeve of mine is lint, hair, and other stuff all over the buds. Nothing worse than smoking nylon carpet fiber or pet hair.