Most schools (and groups) do follow the NSPCC's guidelines and give out good "what's acceptable" advice on adults touching them.
It is usually a throw away remark that sparks off an abuse investigation. One example is (that I was part of) a teacher was settling a child to sleep on a residential and was asked why he wasn't stroking "Rodger" to sleep "like Uncle .. Does when he puts me to bed?" You can guess what Rodger is.
Another is watching the children role play RL and everyone knowing what personal boundaries should be, so they can report for their friends.
Abusers use made up names, anyone working with Children don't ignore "throw away" remarks.
Knowing the correct words doesn't make the proving if a child under 10 any easier, or means that the CPS will take up the case.
Even Vulva isn't always right, my DD's didn't just fiddle in any one place, it was just generally in their knickers.
"Hands off your bits (although mine had WooWoo as well), was a fitting description.