I was having a look at the chemistry of corexit and oil, but there are just too many variables to be able to do testing without the actual products. The interaction between both substances and all the chemical components combined, plus any other variables, such as temperature, sea water composition, etc, would also change things.
Having said all that, I absolutely agree, it is highly likely that the combination of the two, oil and corexit, would produce something more toxic, not less.
Is there anyone in the US doing this testing now? Or are people still relying on what comes from BP/Nalco/US government?