It's great that they exist. It is worth trying, and obviously if it works you should just keep doing this because you found a solution. If this type of content doesn't help though, I think it is still worth trying a familiar story that you enjoy. There is a bit of a difference I think. A story can be really action packed and still help you sleep if you know it. I can find myself losing any sense of time and drifting between different points in the story in my mind. I'll be thinking about how calm and nice a character is, how funny they are in my favorite interactions and how cool it will be when I find out that they were actually the killer all along at the same time. And if the story is familiar none of those actual moments will actually wake me up, because I know that they are coming and I'm already kind of thinking about them beforehand if that makes any sense.