I recall that Religious Education classes were in the curricula of the various (C of E) schools that I attended - but, curiously, I can remember very, very little about them. All that I really recall is that the Bible is in two halves: the first half is full of begatting and slaying and people living in the desert with dishcloths on their heads (that's how my infant brain pictured it anyway); the second half is about someone called Jesus (or,as he's referred to these days, "this man Jesus".). I probably couldn't tell you a lot more about Christianity now! So school didn't succeed in brainwashing me. I suspect that I probably found it all pretty unconvincing then. On the other hand, school did force a lot of useful stuff about reading, writing, arithmetic and science into my thick head.
Still, I'm glad that I wasn't born into a Catholic or Protestant fundamentalist family.