It would have worked today. shorting financials is like picking nickels in front of a ... slot machine
In a free market, C and BAC would gradually tumble towards zero. However I find it hard to believe that the US government is willing to formally nationalise these two companies, despite already throwing huge amounts of preference shares into the two zombie banks. Therefore I think it's possible that a future bailout / insurance for toxic debt would be provided on generous terms, similar to the C bailout from November. As sad as it is for US taxpayers, C and BAC shares could rise if/when the next bailout is announced.