Why should we always be thinking 'I am THAT'? Do we need to go on thinking 'I am a man'? Are we not always THAT?
The idea of 'Dualism during practice, non-dualism on attainment' is also false. While you are anxiously searching, as well as when you have found your SELF, who else are you but the tenth man?
Each one counted in turn but failed to count himself. They thought the tenth man had been drowned and began to mourn.
A passing traveller asked about their grief. He saw their problem and made them pass him one by one giving each a blow on passing and telling them to count the strokes.