Even in the Bhagavad Gita it is said, ’Gahana Karmano Gatih’, even the greatest man on earth is confused on which karma does what. So, best is to surrender all the karma.
Drop thinking about all the karmas and do your dharma and move on.
If you do your dharma, automatically those karmas which can be erased will get erased.
Of course sadhana definitely erases some bad karma and for some karma we will have to go through it. There is no choice or option; you have to go through it.