What this points to is that there is a conflict between the desire of the state to provide education and the obligations of the state to ensure religious freedom. One simple solution, which is what occurs in ireland, is that the state pays the salaries for ALL teachers in the country irrespective of what schools they teach in. Both public (state run) and private schools have the teachers salaries paid for. This allows the state to avoid any complications with regard to religious material presented in state schools, as the state funds all religious schools as well and thus ensures religious freedom. Thus the state becomes responsible for ensuring that any student can attend a school which caters for their religious persuasion, NOT responsible for ensuring that every school removes religious items or documentation. It's then up to individual schools to set the religious outlook themselves, and that outlook becomes part of the ethos of that school. A simple solution to a complicated problem.
Paul.