Well, hopefully we'll soon have the other 4 songs, as well as the whole "Better" version...
I believe that it's the Trunk cd. Darknemus thinks so, and he's the one responsible for this, along with Saint...
If memory serves me right, Trunk acknowledged there were three songs on that CD, with and without vocals. I've heard Prostitute was the third song... Then again, it might be TWAT. One can't really be sure without hearing the disc.