I believe this method is very popular on the fast New Zealand trout rivers. They use an oversize, buoyant indicator dry, an oversize weighted nymph to get the depth and a second nymph of a more normal size that the Trout is more likely to target.
I've never tried it myself, the flows in my usual fisheries being manageable with a single weighted nymph for the most part. I think it would take practice not to get tangles and it could be an expensive business losing multiple tungsten beads in one go.
SharkeyP