1. American mothers have long believed that when it comes to washing out the mouths of naughty children, nothing beats Ivory Soap.
     when it comes tonothing beats. 
2. People were told that Ivory was "so pure that it floats," and the notion took hold.
     took hold. 
3. So many hands, faces, and baby bottoms have been washed with Ivory that their numbers beat the imagination.
     So many that their numbers beat the imagination. 
4. The company's big break came with the introduction of its floating soap.
     (one's) big break came with .
5. Mothers tend to frown on the practice.
    tend to frown on .