So how about 1000 units?
The spill is currently 5000 square miles. Sounds really bad but that’s a square about 71 miles on a side.
If you optimistically say that you can clean up the oil by skimming the top 1 inch of seawater, you would have to process about 87 billion gallons of water and oil.
1000 machines could do it in a just over 300 days. Of course skimming it would take a lot longer.