I'd love to try it myself, but there are a few things that make me worry...
First, we'll have to know what kind of SIM DoCoMo uses. If it's Comp128V2 we are unable to extract the KI.
Second, because of the same reason, our local network's SIM also mustn't be Comp128V2, which means no 3G SIM will work for the hack.
Somebody please correct me if I'm wrong.
Could you give us a bit more information about what the people in that Chinese forum wrote? What kind of SIMs did they use? How did they manage to extract the KI?
I wished I could read Chinese...