Sure, but raking up the muck can definitely stop plants from reappearing in that spot. It's really striking how diffuse muck can be---floating in suspension---and how removing the big structural parts (leaves, sticks, etc) causes what you miss to settle closer to the bottom to the point where plants can't grow in that spot anymore.
I might have mucked out piles that amounted to two or three yards but I'd guess I cleared at least ten times that much in water volume.
