I don't think you will be able to see a noticeable difference with a single use. I have used them several times on a single ball and have noticed a consistency of reaction.
You might see a "dullish" finish if it is removing oil shine lines from the ball. If they did remove some of the oil shine, you should notice a sense of consistency of reaction with the ball.While I cannot yet recommend them (if that means anything) I do feel quite positive about them so far.
While they are not designed as a cleaner, they do seem do a decent job of cleaning.
It recommended that they be used every 2 - 3 outings or every 6 - 8 or so games. I got that from some of the Ebonite folks (not staffers).
I would recommend using some type of glove when using them. I have some nitrile gloves I use for various tasks (including using Clean and Dull). I don't think the chemical is dangerous (so far) but it is very strong smelling and it is new. So I'd rather be safe than sorry.
"None are so blind as those who will not see."