Since it has been a month since the plane crashed, any large debris that was floating, has most likely sunk. The large debris would be the parts easy to see from space or airplanes. A month of wind and waves which can be huge down in that part of the world will have sunk floating plan structure, especially after this length of time. How many storms have they had down there in a month? If is fall in the upside down part of the world which is a bad time of year for bad storms.
I still wonder if the pilot used the simulator to practice ditching the plane at sea. If he had ditched the plane, there is a good chance there would not be much debris to find.
Given the time that has passed since the plane crashed, it will be unlikely to find any large structures from the plane, and any debris they would have to find is likely to be small and hard to see. The search and rescue people have some pretty good algorithms for calculating the drift of a boat/person because of current, wind and waves but I would be shocked if the programs would be that accurate after a month worth of weather. Especially the weather in that part of the world.
At this point, it would not surprise me if the plane is ever found.
Later,
Dan