Remove the giblets from the chicken, rinse inside and out, and pat dry. Wash your hands.

Peel the garlic from one head, separate the cloves from the other but leave unpeeled. Slice one of the lemons into four wedges, the other into eight wedges. Place the 4 lemons wedges and the unpeeled garlic into the bottom of the slow cooker.

Season the cavity of the chicken liberally with salt and pepper. Fill the cavity with a mixture of the remaining lemon wedges, peeled garlic, and herbs (about 2 handfuls).

Place the chicken in the slow cooker. Pour the melted butter over the top of the chicken, season with salt and pepper. Cover and cook on high for about 5 hours. Baste the chicken every hour and a half, if possible. This isn't necessary but does make the the chicken more flavorful. Cook until the chicken reaches 165 degrees in the breast.

If desired, remove the chicken carefully from the slow cooker and place on a baking sheet. Broil for 10 minutes or until the skin is crispy. Strain the liquid from the slow cooker, skim the fat from the top and serve with the chicken.