Self-investigation (ātma-vicāra) entails nothing more than just being persistently and tenaciously self-attentive

In a comment on my previous article, Why is it necessary to make effort to practise self-investigation (ātma-vicāra)?, a friend called Pachaiamman referred to the first section of it, We must practise ātma-vicāra for as long as it takes to destroy all our viṣaya-vāsanās (in which I had cited extracts from the sixth, tenth and eleventh paragraphs of Nāṉ Yār?), and asked:

May I give a short description what happens in my poor experience of practising self-investigation in the following passage: The attentiveness with which one investigates what one is has to be accomplished by the ego. The ego is a bundle of thoughts. So attentiveness is also a thought. The attentive thought ‘who am I’ is entrusted to try to extinguish/erase other rising thoughts and simultaneously or after that to investigate to whom they have occurred. It is clear that it is to me. By further investigation ‘who am I’, I do not clearly recognize if the mind subsided or returned to its birthplace, that is myself. Because the same (my) attentiveness has to manage to refuse the spreading/developing of other thoughts (without giving room [place/field] to other thoughts) and rather eliminate them, other thoughts are on my mind well waiting for refusal of their completion. Thus I am far away from grabbing the opportunity that the thought ‘who am I’ itself is destroyed in the end (like the fire-stir-stick). What is wrong in my strategy or where I am on the wrong track?

The following is my reply to this: