Going to have to see some serious citations to take this out of magnetic wrist strap territory. Can you provide a citation that playing a sound during a particular phase of sleep actually does something?

Over 50 published peer-reviewed studies and a decade of research.

https://www.affectablesleep.com/how-it-works

Bottom of the page.

Don't think of it as "sound", this isn't "gentle tones to help you sleep", and it isn't played during a particular "phase" of sleep.

It is specifically targeting individual slow-waves.

Think of it more like applying an electrical stimulation to a muscle while lifting weights, not just pumping heavy music into the gym.

Closed-loop neurostimulation, not neuromodulation.

However, you are 100% correct that overcoming the snake-oil factor is a significant challenge for us.