Too Much Editing?

     How much editing is too much editing? That's my question for today (and for, well, all-time).
     I've lost count of how many times I've edited Daze and Knights. I'm not regretting the edits. I know my MS has just gotten stronger and stronger each time. But I worry about getting to that point where I've completely edited myself out of it. Or edited the voice out. Or edited those sentences that are my way of saying things.
     Agents want your MS to be squeaky clean. I get that. They don't want you to tell them it still might need edits. I totally get that- why anyone would point that out in their query is beyond me. But how do you know when it is squeaky clean? Do writers actually reach that point, that moment? Do they have that thought of, "I've done all I could, it's the best I can make it, now it needs to prove itself out in the world"?
     I don't think I've ever had that thought. No correction. I've had that thought after each and every edit. And then I go back and there's always more to fix. I can't help but think there will always be more to fix. So how do you stop editing? What makes you stop editing that MS for the last time?
     What do you other writers out there think of this? Because I'm thinking this time (like every other time before) that this edit will be the last one. That I will query again for a bit and if I get nowhere than the book will be shelved for good. Or at least ten years or so. But I know, deep-down, that I could edit it again in the hopes that one more edit might do the trick.
     So how much editing is too much? When do you stop? When do you say, I've done enough?