Bid is for simplest miner, CPU-only, no long-polling, no rollntime, no midstates. OpenCL isn't supported by Flash Players, and GPU acceleration is automatic for graphics only. You won't get high hashrates, but if you're thinking of farming visitors via Flash could be economically viable enough, especially seeing how BTC is over $90 at the moment. I can't say how many MH/s would you be getting, though, probably not even M but kH/s. Message me for more details, discussion.