Plausible theory, aside from whether or not it works. Is a bit too close to a generational parasitical family type thing to not be a little creepy. Kind of like breeding children for parts and fluids.

The 'young blood' transfusions have been popular for ages. Was even a company near me that did them a few years ago. $8K per pop, if I'm remembering correctly.

This seems like a practice that would resonate with the secret cult societies that run most of our world. In everyday life, social security and generational households are similar concepts. Physically using your children for fluid production doesn't seem like a cultural practice you'd really want to catch on.