I have never had this, but have a manager whose family swears by it.
Every Thanksgiving, he buys about a dozen White Castles and his wife makes their stuffing from them. Several key ingredients are there--meat ( I think) bread, onions. She just adds celery and spices, puts it all in a food processor, and voila. There adult kids request it every year, and won't eat anything else.
The recipe is out there on the net, for those who want to give it a shot.