My Orkin guy told me to put a tablespoon full of bleach down every drain in the house, including the bathtub/shower drains & overflow holes on bathroom lavatories. This is where they breed. He said to put it down the drain before you go to bed at night, DO NOT run any water, until the next moring. This will wipe out their breeding gound. Try to avoid getting the bleach on the chrome parts, remove them, if possible.