Agreed if your (chicken) breasts are skinless. They will have absolutely no flavor as farmed chickens go.

WRT crockpotting a chicken for 10 hours, you may need to somehow brown the bird first in order to caramelize the sugars. And perhaps adding chicken stock and salt to amplify the chicken-ness.

Or, as thelark suggests, roasting or grilling may be a better way to go especially with a free range bird.

David