I have to agree, hair hygene is pretty low on my list.  Though if one has lice, maybe it would be more important.  Then I'd personally just shave, but I hear gasoline kills lice too.  Not that I really endorse that idea (Michael Jackson rerun, anyone?)
Where I live right now, I'd just dunk my head in a bay somewhere.  which probably would leave me with enough oily residue to bring up the topic in the above paragraph.