The situation here is that one has to sign a form when one wants their child to not participate. It used to be one had to sign a form to participate. So I just sign the form for my daughter to not participate.
For her, it would be a waste of time anyway. I sat her down at 5 years of age with the 3rd ed. of Campbell's Biology and told her the truth. Not unlike other subjects, where I have to supplement her classes in public school with additional teaching.
System appears to work, as a teenager, so far no premarital sex and no STDs, 22 in ACT in 7th grade, missed just 3 questions on TAKS test last week. Parental involvement in education works just fine here.