Place chicken in a 3-quart crockpot. Top with 1/2 cup Frank's RedHot Sauce. Cook on LOW for 4 hours (6 hours if frozen).

Mix ranch mix, mayo, sour cream and milk in a pint size mason jar. Cover and refrigerate for at least one hour before serving. 

Once chicken is cooked, remove it to a bowl and shred. Add remaining 1/2 cup hot sauce and mix to incorporate. (Add more or less to achieve desired spice level.) Allow to cool. 

Remove celery stalks from the bunch and rinse well. Cut into 4" pieces and lay on a platter.

Stuff celery with buffalo chicken mixture. Drizzle with ranch dressing and top with dried parsley. Serve immediately.