I did it another way... the simpleton way hahahaha..., i just extracted all the listfiles from all the WoTLK MPQ files XDD. merged them all into one text file, dropped it into excel and removed duplicates. saved out the remaining list as a batch file, dropped it into notepad++ and ran a macro on it adding DEL " and ending it with a closing quote, so it's like
del "worldblahfile.m2"
del "worldwmoblahwmo_000.wmo"
etc etc
and i'd just run it in the folder where I did my extracts in and it usually takes care of it pretty well, ofcourse I've edited it a bit to remove things that I don't ever extract like Shader and Sound files and to avoid deleting dbc files.
I've attached mines if you want to try using it or just to get a better idea of what i was rambling on about, though it could take pretty long to run through it since it does have a lot to go through and all.