You can't because they are not the same.
The Confuser contains questions which are the same style as the real ones. Occassionally they will be the same. But the multiple choice answer patterns will be different.
If you can revise from the Confuser until you are getting 80%-90% then you are sure to pass the real exams.
It's like the FAA exams - the question banks are public (as they are for the JAA IR) and you can do the same with those. But one cannot learn the answer sequences by rota because they get changed around.
I don't think this is not "proper study". By the time you are getting say 90% with these revision tools, you will understand the subject matter just fine.
"Proper study" might be reading the Trevor Thom books until you are blue in the face, and you will not pass the exams on that. The CAA exams are full of word tricks and quite a few of the questions are ambiguous - it would be difficult to pass the exams if you merely knew the subject! Moeover, the exams were written on the assumption that people swatted from certain material - again if you merely knew the subject from some other source (like having been flying for 40 years) you would have difficulty passing.