Probably a couple hours total, usually with some carrots and onions and any leftover gravy, gel and skin. I leave the meat on and then pick it off by hand afterwards (it pretty much falls off the bones by then) to ensure there are no bones or cartilage, etc. in the final product. I then strain the liquid, thicken it and season it and return the meat to the "gravy." I sometimes add some bullion if the poultry flavor isn't strong enough.

This process works well with leftover rotisserie chicken too. If we're going to have a dinner party (remember them?) serving souffles and creamed chicken, I sometimes go to Costco to get a rotisserie chicken for this very purpose.