i got no idea how u are working that with layers-but i only did photoshop for 2 months though gotta admit to that. When i needa extract something i use magic wand-magic eraser and ordinary eraser-it doesnt take long i think-if the magicwand cant be set to do it properly then i use the magic eraser and do the rest by hand. If its of any use to you you can while using the ordinary eraser hold shift down then it regenerates the original pic if u got lost in the history...