It depends what is your definition of sining or what are the sins.
Of course we should not do major sins with half-absentmindedly repeating estegfar-as that is a very bad adab. We must avoid sins.
For example if you are invited at a decadent party/wedding etc. and you can not refuse a round or two of dhikr/estegfar without drugs or alcohol is a very good idea.
Changes in person most often are a stepwise process.
We have daily, monthly, yearly...lifetime timeframe and we must invest well our efforts as in surah asr.
Similarly working at work (of course we make duas, salawat, dhikr if idle time) is not meant to be like without productivity, donr jobs, tasks etc.
What you meant by estegfar is a part of that process of change/metamorphosis/athanor/transmutation/how different people call it.
As a child learns we need to learn too.
The heart/mind to be present, we need to get throught knowledge, understanding, practical examples and wisdom.
We need to reflect upon names of Allah. There are published books even by Saudi scholars giving examples of Quranic and hadith sources connected to asma. I bought recently one similar book in four tomes (1000+ pages).
In beginnings say we know the basic Arabic meaning of estegfar wording. We have a good niyyah, sincerely asking Allah.
We should not be to hard on ourselfs and thinking that we do it absentmindedly and that we require some higher stages of consciousness.
Afterwards we learn asma and related (there are a lot, lot of hadith and with time we learn new and new ones) hadith to say some longer, like astagfirullah al adheem alladhee la ilaha illa huwal hayyul qayyumu wa atubu ilayh, meaning.
With time you notice changes in yourself and around yourself and you get understanding and wisdom.
With more advanced practices that is greater and greater and if consistant and advancing you are going into changes, dhulm leaves, noor and mercy enters, you heal etc.
It is known even from salafi accepted literature like Ibn Qayyim or Ibn Taymiya works that estegfar and dhikr induce great changes.
There are their multiple works in tomes about that.
