I have used these products for many years on paint and glass with out fail. And so have many others. I didn't come up with this combo, its a well tried and tested combo for very long period of time.... The internet is full of its praises.... I am no Christopher Columbus!
If it does not work for you, it could be due to a number of reasons, including not enough glass prep.... I would say give it another go.
As everyone knows, I only recommend products which I have personally used and found useful.... Most of the products I used are on my YouTube videos as well, where I test these theories.