After some searching around my harddrive, I found where GB stores it's loops. This folder on your HD has a few subfolders that loops are installed to. I'm not sure if just dragging the loop will remove it from GB's index of loops, but it's worth a try.
The location is correct, but instead of putting everything to trash, believe me, I had to reinstall OS X for a year..., burn them to cd and save 1.3 giga.