Slice off tops of squash and enough of bottoms so squash will sit upright. Scoop out seeds and discard; set squash aside.
Combine rice, onion, celery, cranberries and sage in small bowl. Stuff each squash with rice mixture; dot with butter. Pour 1 tablespoon orange juice into each squash over stuffing. Stand squash in slow cooker. Pour water into bottom of slow cooker.
Cover; cook on LOW 2-1/2 hours or until squash are tender.
Notes
The skin of squash can be extremely tough! To make slicing easier, microwave the whole squash at HIGH 5 minutes to soften the skin.