Audacity and other audio editors are nothing in voice removal process.
btw, ill tell you the truth - you will never can get rid of vocals without corrupting the overall sound of track (vocals settles in every freq of sound), the best way is to rewrite track without vocals, i can do that for 15 bux.
my name is Oleg, im a producer of German rap artist, co-producer of US soul artist (doing all music/audio/graphic jobs), running several own bands, occasionally doing various ADV/game/toons music, i use FL Pro, Audacity, Izotope and other DAW's and soft in my work, please refer my profile or contact via chat for more information, thank you very much.