Smart headbands claim to make people calmer. Do they work?

I've been using one off and on for about 4 years.

They work in the sense that it helps people quantify/gamify meditation practice, which can work as positive reinforcement.

I also find it much more relaxing than guided meditation.

If you're unlikely to continue a meditation practice, you'll probably use it a handful of times and will end up in a drawer, and you pull it out occasionally as a novelty to show people.

Still, would recommend.

I would love to have a reliable device for at home Neurofeedback training bit I find these products quite questionable, especially of they have dry electrodes, also they require correct usage as muscle contractions can easily kill you readings. Researching which ones are BS and which ones might be usable is also quite difficult as I have not found a reviewer who is knowledgeable in the subject, if you know one please comment, I‘d love to figure this out.