I taught for a home school group for a few years and it was quite effective. (We submitted tests and essays to an independent organization that certified the students’ diplomas.) I was shocked at how little time many students needed to complete a lot of the work, and how effective it was to spend 4 or 5 hours on an essay or math problem before taking a break. These were often projects and skills that in a regular schedule would have taken a month or more. Students were then able to more leisurely — or intensely — take up a novel or other project, while I could continue to work with the kids who needed more time for mastery.