Okies, chunk, I had no intention of being condescending, I just wasn't sure where the question was coming from. As to your larger question, "has it been tried and failed?" Boy does that open a can of worms!

There's a whole continuum of "socialist" philosophies that run the gamut from Social democracy through Democratic Socialism to outright Communism. There are "purists" in each school, and "adherents" who mix and match based upon their personal foibles that confuse definitions even among professionals. Like most political science junkies (it was my undergraduate major), I'm opinionated and use my own definitions and distinctions. The problem, in my view, is that is a field that mixes economic, social, and political theory (sometimes Willy-nilly) in not always clear (And often deliberately obscure) prose.

I'll set up my personal framework to try to make sure I'm not "one of those", as best I can. I started a thread to do exactly that, but deleted it in favor of this one, and in order to honestly answer your question. What makes the question difficult is "has it ever been tried" - and what we mean by "It" and "tried."

"Socialism" is used in so many different ways that its real meaning is debatable. In economics people generally use socialism to mean "public" (either government or social cooperatives) control of the means of production - i.e., who owns "the capital" - real estate, machinery, money, profits. In politics, people usually mean the goal of using "government" to help "The people", and, again, it runs the gamut from complete authoritarian (communist) control to left-leaning democratic market regulation or manipulation - the so-called "mixed economy". Around the world, virtually every economy is "mixed" in both an economic and political sense. Add in "social theory", and you end up with a bloody, rhetorical mess.

I generally describe myself as a "Social Democrat", or progressive, in that, I believe in democracy as the form of government and social as the goal of government programs, but accept that the economy is market-oriented and capitalistic in nature. So I support wage supports, social welfare programs, government regulation (and even bending) of markets. In some areas, I believe in public-private competition in the markets, e.g., "public option" health care, social security, public agency pension plans, and even public production of commodities/services.

So, when I quip that Marx wasn't a very good "Marxist", what I mean is that he developed a social theory of how the political-economic system worked, and how he expected it to naturally develop, then actively interfered with that development by fomenting revolution and seeking to impose a communist framework from the outside. It's like a scientist proposing a hypothetical then manipulating his experiments to "prove" it.

If by "It" you mean "social" control of the means of production, "It" had been tried in an authoritarian-communist form in several locations (China, USSR, Vietnam, Cuba). If you mean organically developed "socialism", only on a small scale (e.g., cooperatives, utopian villages, communes). On the larger scale, social programs have been tried in numerous locales instituting social welfare programs from socialized medicine, public welfare programs, public retirement programs to state control of national resources. "Success" is too often determined by the eye of the beholder.