Okay, the whole story: I'm the IT guru for my ex (Barb, with Yosemite) and my daughter (Holly, with Win 7), and I use TeamViewer a lot when working on their systems, so I don't have to travel to Barb's house or put up with Holly's noisy undisciplined kids (right across the street).
Both of them have the tendency to have umpteen windows open simultaneously -- Barb set the record recently with 21 open windows! (Don't ask!) I just want to get these windows out of my way so that I can get some work done. Win 7 has a nice little rectangle in the upper-right corner which minimizes all open windows, leaving me with the Desktop -- perfect! That's why I need Command-Option-M. I'm not familiar with Mission Control, so I took a quick look, and I don't think that's going to give me what I need. (I just took another look at your post, and it sounds like what I need. I'm going to have to get into it deeper to figure out how to make it do what I want.)
One other problem: Once I get C-O-M working, then I'm going to ask around for something that will "expand all minimized windows" when I'm done, to make it easy to reconstruct their garbage piles.