Yes I tried that method once, too, without success and leading to crash on different computers, I can affirm that so far that this doesn't work for the most ..
But speaking of .bnk files, have you ever tried to open 'gen.bnk' in NFSWizard? This leads NFSWizard to an immediate crash even if it is yet smaller file size than my current reworked siren.bnk, don't know why, perhaps a compressed audio codec that NFSWizard hasn't implemented or whatever ... would be nice if one could alter that since it also contains those omnipresent ambient sounds (background sounds) like that church bell, the mooing cows and also that annoying German croupier I think which is only speaking English
etc ...) and also the passing traffic 'rush' sound and the diesel engine sound of traffic Buses and Semis which is somewhat poor and always just idling
I have exported it and tried to open it with other tools and also tried to play it with Media Player Classic that has so many different audio codecs implemented, none had worked