I don't know exactly how much sodium is removed but....
My mother was told by a doctor to drain and rinse canned vegetables before
heating them. This was an easy thing to do to reduce the sodium. Pickles,
for example, are still too high in sodium. Of course, you are aware that
canned soups, broths, sauces, etc., are very high in sodium. The items
marked "reduced sodium" are better but frozen goods without sauces are
better yet. Cooking from "scratch" is best!