Shock Chlorination

Chlorination is widely used for the disinfection of raw water in the pre-treatment stage in desalination plant. Some technicians believe that continuous chlorination in the range below 1 ppm makes bacteria tolerant to the disinfectant. They suggest shock chlorination of a few ppm chlorine on the upstream as a more effective remedy. To what extent do you agree or disagree with this view? Does anybody have any experience in this regard?