Actually it's been proven that head lice do not survive long away from the human head, so other than pillowcases, brushes, hats etc you shouldn't need to go overboard with washing sheets/towels etc.

Thank goodness!!
I was just about to post something similar, i spoke to a chemist lady who had just come back from a conference about nits, this was last year, what she told me was that the new studys are, that they dont have knees so cant jump from head to head and once off the head they dont survive past 24 hours, so she said, u dont need to wash everything, just shake ur pillows and doonas, and vacume the floor.

When i dont have any moov in the house, we do the conditioner treatment as well, and vinager.