Cleveland Police said there had been a 50 per cent drop in re-offending rates in Stockton after the launch of a scheme to tell young offenders what it was really like in jail.
Special sessions are organised in which a prison officer tells the youngsters, who have all clocked up their second caution, all about slopping out and bullying. They also learn about restraints and equipment that can be used on inmates.
Parents or guardians accompanying them have been equally shocked by the "warts-and-all" presentations. One boy's father said: "There's no excuse for him getting into trouble again now he knows what to expect if he does."
Inspector Ian Birch, who helps run the scheme, said: "One unforeseen bonus was that other members of the family, including brothers, sisters and friends of the person to be cautioned also attend on a voluntary basis.
"Consequently peer pressure to commit crimes may be reduced as more people than anticipated now know the consequences of committing crime."