I don't know about this particular can of wax and grease remover but when I looked into this a number of years ago wax and grease remover was much slower than most anything you could get cheap.
Listen, wax and grease remover is according to your numbers $11 more than Mineral spirits at the "McHome" store. How long does a gallon of wax and grease remover last? Let's say you are doing completes, how long is going to last, three or four cars at least, probably more. So that breaks down to about $3 to $4 dollars a car savings.
How much are you spending on materials to paint a car? How about the labor to paint a car, how are you spending? How about that beer or smoke you are having after?
That $3-$4 isn't jack squat, for goodness sakes use the stuff the paint company makes for this very important step in the painting process.