I am a public school teacher and allow me to say: Bullschmidt. Homeschool. If there is a particular area in which you are weak, supplement with tutors or something. Even if, at 18, they were doing worse academically then public school kids, they are undoubtedly better off psychologically. They can take a few remedial classes at community college to buff up wherever a parent may have not caught up and be ready for college soon enough. And best of all, they will have spent their formative years being molded by YOU instead of liberals and all the little neighborhood brats.
What do you teach?