I will say that it sort of works if you keep it realistic. Example:
When you wake up in the morning, visualize yourself having a good day at work while saying "this is how my day will be today". You will feel like you had a good day at work, even when it wasn't really any better than before. Why? Because whatever you think is going to happen, you start looking for evidence that it's happening, and so you see that more than the other.
So yeah, visualizing something like rainfall in the desert probably won't work. But visualizing yourself having fun and making lots of money when you have the sort of job camgirls have (where having fun tends to make more money than being bored), and you'll have more fun and make more money.
Visualizing yourself making a $10,000 paycheck only works if that's actually possible in your current state. So, if you have a min wage job, visualizing that paycheck will only help if you then put the effort in to make it happen. The secret is that if you believe you will fail, you will fail. If you believe you will succeed, you will succeed. But you have to actually instigate it. You have to actually work for the thing that you want. So you visualize that paycheck while you go to school for a career in which that sort of paycheck will happen.
The other half of the secret is confirmation bias. As stated, we look for confirmation that what we believe is true. So if you believe you will see a bunch of red cars, you're going to notice a ton of red cars. The number of red cars didn't change, but you notice them more because you're subconsciously looking for them. So the guy who finds the parking spaces. It doesn't work like he thinks. He just notices all the times it happens, and ignores all the times it doesn't. But, he's a lot happier believing that it really happens.