The sound folders are empty because the sound files ARE in the .vpk files.
I'm sorry, I mean't vpk, not vcd.
Also, keep in mind, if it's a CSS sound, it'll be in the vpk file in your CSS root folder, not the gmod one. Same goes for HL2, EP2, etc, etc.
Some games have more than one vpk file so you might have to find the right one.