Also, it's not an outrageous claim; soundcards do DSP processing, technically it is possible (however extremely unlikely) to program them to do SHA-256 hashes.
(Note that I'm not saying the claim the OP is referencing is true, or that the hashing speed would be high)
What whould take for someone to try it out? as far i known the main problem is that Creative chips uses a very very privative "api" to do stuff on them, and there is 0 documentation about.
if a EMU10K1 can give 10mhash/s it will be nearly power efficient as a FPGA, at much lower cost.
If its possible i think it worth the try.