My mum believes in this and got me to do it when I was looking for a place to move to when leaving abusive XP. So just to troll it, I specified a house or flat, within walking distance to town, which has its own entrance (for my cat) and no steps (for the buggy), and a bathroom on the same floor as the living area.
House I'm living in now meets all of those criteria - and weirdly enough, the bathroom on the ground floor thing isn't that common in this area, despite living in a victorian terrace - most people on this street have either extended upstairs to move the bathroom, or converted a bedroom in the 3-bed houses. And it's not like I had loads of choice either, because none of the agencies would accept benefits without a guarantor earning more than anybody I know, and most of the private lets were No DSS as well. It was pretty much the first place that I was accepted at, rather than having the choice between a few.
I think if you're going to put faith in any kind of system like this it's important not to just expect the universe, or God, or whatever, to provide you with something blindly but to accept that the form of "help" the universe provides could be a path to achieve that thing by yourself.
I agree that it's more focusing your mind on what you want, but I think it's an interesting theory. It's said, BTW, that if you are constantly thinking "I want X" then "the universe" will keep you in that state of wanting, because you are focusing on wanting it rather than "X is going to happen" and, similarly, if you are constantly thinking "Ugh, I have no money" then again the universe will keep you in that state - which I actually find really stressful to believe in, so I try not to think about it. I don't want to police my own thoughts. It's exhausting. I've actually ended up with an OCD-like behaviour where I have to think "We are safe. We are safe. The house is safe and I am safe and DS is safe and we are all safe." every night before I can go to sleep, because I worry that if I don't think this, I will slip into the obsessive thoughts I constantly had as a child about house fires and that will somehow cause one. And I don't want to think about the connotations if everyone's thoughts actually had any kind of effect on the physical world.