Rub salt onto chicken breasts and place in bottom of crock pot.
In a medium bowl place onion, celery, cranberry sauce, orange juice, dry mustard, cinnamon, lemon juice, honey, brown sugar and chili sauce. Stir and pour over chicken breasts.
Place lid on crock pot and top with kitchen towel using instructions in description above. (My crock pot is only 3 months old and I still do this.) Turn crock pot on high and allow to cook 1 hour. Turn on low for 3 or 4 hours. NOTE: I have tried leaving crock pot on high the entire time and this dish was done in 3 1/2 hours.
Lift lid and quickly place orange slices over chicken without stirring. Cook an additional hour.
Combine cornstarch and cold water. Add last 10 minutes of cooking time for thickening purposes.