Please read his message again. You've misinterpreted it.
Quote from MH "lice can only live where their is dirt enough and that dirt is internal"
Only where there is dirt enough and that dirt is INTERNAL, which means on the INSIDE of your body. If your diet is the standard american diet, then there is dirt (toxins etc) INSIDE your body. Without this, the lice can not thrive.
He's not saying on the outside that one is dirty, he's saying on the inside.
If that's offensive, I don't know what to say. Aren't we all here to find a better way to live? And part of that is cleansing, improving diet, etc.