This question does not have a simple yes or no answer. The answer of whether or not an online course will be effective is determined by the individual.
If and only if the student has a strong desire to learn will the online classes even have a chance to be effective.
Also it has to do with the individual teacher and how much information they can relay without face-to-face interaction.
Come to think of it, there is one more way that this arrangement could be successful and that is if the parents take a very active part in the students learning, and take over, much like the student is being homeschooled.
But, for the most people, I feel like online classes won’t work, both student and teacher must be held accountable in order for a successful online course.