I too would try a bit in some water. Maybe a quart or so. You sorta have to know how much you are putting in, a teaspoon, that sort of thing. I would start out on the light side and add some more, keeping track of how much I was adding. Then when you get to the taste you want you know how much to add it the future.
Or I might just go for it and add a little bit at a time to the soup mix and try it after each addition.
Before criticizing a person, walk a mile in his shoes - then you are a mile away and you have his shoes!