The Catholic schools were also Prussian-model schools. When I attended Catholic schools my textbooks were the same as my Protestant neighbors. The publishing companies mere modified them slightly for the Catholic system.
But the kids coming out of the Catholic Schools were actually educated; even minority kids, during segregation! It has only been recently that Catholic schools have devolved into the silliness of other schools, because there are more lay teachers now who are educated at the typical universities with all their propaganda.