In a large bowl, stir together herbs, pepper flakes, salt, pepper, juice and oil. Add chicken and toss to coat chicken with mixture.
Lightly spray 5- or 6-quart slow cooker with nonstick spray. Add one layer of chicken. Top with half of garlic, celery and onion. Add remaining chicken and vegetables.
Pour in wine and broth around the edges.
Cover and cook on low setting for eight hours. Season to taste with salt and pepper. Serve in shallow bowls topped with generous amount of finely chopped parsley. If you like, you can serve this soupy dish in a bowl over a mound of couscous or brown rice.