It might have worked, assuming that there were enough warehouses of product to cover a spill of tens of millions of acres. Not so with the use of Corexit.
We are told by some of the rosy MSM reports that oil eating bacteria are responsible, along with evaporation, for all the oil disappearing. Yeah, right - as if there were such a vast, vast amount of oil eating microbes just lying there in the gulf seawater without such a huge source of oil to sustain them prior to the blowout and if they could somehow survive the Corexit.
The catch is that you would have had to let the oil make it to the surface, and that is what BP has been poisoning the gulf to prevent so they can cover up the true extent of the oil and limit their liabilities. Better to save their arses than save our lives or the environment.
There is no real solution other than time and nature. Nature will always ultimately find a new equilibrium, but it won't be the same as it would have been without the oil and dispersant, especially the dispersant.
The best thing they could do is immediately halt any further Corexit, and try to collect the oil or even use microbes on the surface. That and tell the truth about the extent of the damage and the dangers that are there now and which lie ahead.
Relief wells may help and they may be able to find ways to help stop some of the other leaks out there, but nothing is likely to stop at least some of the oil leaking out through the damaged seabed.