I use usb loader gx and never had a problem using codes and what not.
gct file goes in Codes
txt file goes in txtcodes
plug that sh*t in
What i always do tho is just edit the txt file adding the new codes or deleting whatever and on gx click on brawl open ocarina check whatever codes click create and BOOM
for more people reading this was just a waste of youre time :p
i tried it and again the normal roster maybe its my iso