Please read my post #49.
My four year old daughter learned the “F” word on the kindergarten school bus.
If preserving the innocence of child is important, do NOT NOT NOT send them to a government school or many private schools.
Might need to keep them locked up in house, as well. When the Missus heard our homeschooled son screaming the F word at his dog and inquired where he heard it, he said he read it on a wall they passed on a walk they took together. Phonics is powerful stuff.