I agree that management is much more complex than books or simple theories claim. I think one of the great difficulties people have in evaluating management concepts is that the complexity (and interaction) makes it very difficult to evaluate (especially using accurate data).
Still, I think great management ideas are found in the thoughts of leading management thinkers (now it is true most I think most "writings or speeches of gurus and consultants" don't provide much use but the right thinkers do offer great value).
As Dr. W. Edwards Deming said there is no instant pudding for management (no quick fix). And management requires customization to the organization. You cannot just copy management practices from one place, where they are successful, to another. You can learn from what has been successful and adopt it to your organization if you have knowledge and theory and know how to test (pdsa) the effectiveness of new ideas in your organization.
I don't find many of the "secrets" mentioned to be the greatest ideas for management (the best ideas I find among the thoughts of Deming, Ackoff, Ohno, Provost, Csikszentmihalyi, Hoerl, etc..
Still, I believe it is good to learn about what others are doing. Then, as with brainstorming, what you learn about may lead you to a new idea that will work for your organization (you may also get lucky and find something that is almost directly applicable).
In his first effort, Proebsting chose 25 programmers and quality-control testers from a team of more than 50 working on a new Windows testing application. Via an internal website, workers could buy shares for the month they believed the product would ship. Shares were valued at $1 apiece, and the engineers drew on accounts stocked with $50 each to fund their bids. Within minutes of the site's launch, shares for a February ship date shot up in value while those for November, the scheduled release date, dropped to almost zero. That came as a shock to the project director, who had heard nothing but optimism in meetings and e-mail updates.
This is one example of an intriguing idea I see here. I think I would see it as a management project that had a very high chance of failing (not providing a reasonable value for the effort expended). Partially this is because working to apply this would put you in largely in unknown territory. This has not been applied for decades by many companies and been refined to a point where experience has shown the strengths and weaknesses in this approach such as: what types of things is this a useful tool to manage.
I've read about similar attempts with decisions on what drug development to fund. Here are some more articles on this topic: The End Of Management? - All seeing all knowing - Trying Out the Wisdom of Crowds