When it comes to lice, one thing we can count on is controversy: Is it true these insects have become resistant to lice shampoos? Do any of the alternative treatments work? Are no-nit policies effective? By John Hoffman THE ISSUE: LICE SHAMPOOS What we've heard For five years or more, parents, teachers, camp directors and daycare operators have been saying lice have grown resistant to pediculicide shampoos - the standard drugstore remedies. Other experts say the big problem is people aren't using the pro-ducts properly, and kids are becoming reinfested after treatment. Now scientific evidence shows parents and others were right. If you do a Google search on head lice, the first two sites that come up are the National Pediculosis Association (NPA), a Massachusetts-based …