I believe this type of education can be helpful for teaching children to beware of strangers and acquaintenances, but not so helpful in cases where they are abused at home by family members. Of course, if children were taught at school that they can, and should, report abuse at home, this might help them overcome the threats and/or other types of silencing from their familial abusers. It would depend on how horrific the abuse is and whether or not the child is willing to be taken from the parents. Sometimes it's a situation of "the devil you know versus the devil you don't know" with children, as well as with abused adults (spouses or significant others).
Anything that may be remotely helpful is worth a try, in my opinion. Child abuse, particularly sexual abuse, is the scourge of this world!