Atonements for sins

The fifth canto explains the names of 28 different hells and the numerous types of punishments meted out in these hells. It also explains the corresponding type of hell the sinner shall reach based on his sins.
In the sixth canto Maharaja Parikshit asks, ‘Can’t these sins be totally nullified? If one performs the right atonements, wont the effect of the sins be eliminated?’
To this question, Sri Suka responded thus,
‘The expiation rites can surely eradicate the sins. One need not have any doubts about it. However it will only nullify the effects of that particular sin. Moreover it would only remove the sin, but not the thoughts (latent tendencies) of performing such sinful acts in the future.’
Srimad Bhagavatam explains this truth with a wonderful story.
We all know that the body of an elephant is so huge in size. The mahout bathes the elephant using a type of stony brush. To clean the huge pachyderm, the mahout has to keep brushing the body repeatedly in a pond, by repeatedly changing the posture of the elephant – making it stand for a while, sit for a while, lie down for a while – in short, spending hours of elaborate effort.
After this long and tiring effort, the mahout takes the elephant ashore and he gets into the pond for a wash. Even while the mahout is washing himself, the elephant would suck in sand and throw it all over its body!
Similarly, the expiation rites can get rid of the particular sin, no doubt; but even before the atonement of that sin is effected, numerous thoughts of repeating such sinful acts rushes in the mind!
The Lord’s Mahamantra not only remove our sins, but also gradually gets rid of the thought to repeat the sinful acts.
The story of Ajamila is mentioned in the 6th canto of Srimad Bhagavatam to elucidate this great truth.