Erm you have to actualy use the left over chicken to make stock which defeats the object usually. If i were you next time you go shopping go buy a tub of Chicken gravy granuals. and then just make them up as and when. If not it's boiling the bones and juices in a pan for about an hour.
proper chicken stock is.. coupleof roughly diced celery, carrots and onion chicken bones and giblets saute bones till brown add giblets and veg and cook till soft, add a little water to lift the caramised bites off the bottom of the pan. add amount half the amount of water ontop of how much stock you want(1 and a half litres for a litre etc) and simmer until its reduced to the amout you want. skim any oil or scum off the top with a spoon and strain a couple of times. or buy chicken stock powder, its better than cubes
I used an oxo cube yesterday in ellas meal, I checked the back and it didnt have a salt % just said salt, so I presume it is very low levels?
Tried to check on good old Google but doesn't seem to wanna give you any more info than 'salt'! The oxo website doesn't even work *sigh*