To Train Up a Child, by Michael and Debi Pearl, is a dangerous book. The Pearls' teachings have been linked to the deaths of Sean Paddock, Lydia Schatz, and Hana Grace-Rose Williams.
The Pearls advocate using switches on babies and young as six months, and spanking older children with belts and plumbing tubes. Their book, To Train Up a Child, under the guise of "biblical discipline," encourages parents to beat their children into submission, withhold food, and hose them down outside when they soil themselves.
Here's a quote from it to give you an idea of their approach:
"If you have to sit on him to spank him then do not hesitate. And hold him there until he… Read more