Yes, visualisation works, but not in the miracle kind of way. It only works if the consequence of visualisation is conscious or unconscious action towards your goals.
It's best to think about it as a mindset.
So, for example, after my acrimonious divorce I was barely left with anything - he got the house, most of my savings had gone into finding a rental within school vicinity, my job was (and still is) shite. But I visualised my mind was set on owning my own house again, with a small, but functional garden and enough storage space, sutiable for me and my kids.
That was the visualisation part and it became ingrained in everything I did. I saved like mad, forced a minor promotion at work (not just by working my behind off, but actually had HR kick my boss's arse when she tried to refuse it), took on some extra bits on the side, started looking and viewing and I am now in exactly the kind of house I wanted to be in, with a reasonable mortgage, too.
I am now in the process of changing jobs and am visualising exactly what I want (a promotion which gets me the job I have done better than my colleagues who are already in the role). But the visualisation alone won't do it, so I have also acquired the experience I need to move forward, am volunteering for projects at work to gain the little extra, and am applying for anything that comes up, which carries that job title. I am sure that it's a numbers game as experienced and competent people in my area of expertise are rare. Where the visualisation helps is with the confidence I now have at interviews.
But I've done this all my life. Visualisation is, essentially, just another way of obsessing over something until you get it. I've done a lot with it - smashed grades at school, moved countries, overcome shit stages in life, aced single parenthood, now the house and career - relationships are next.