A sin which initiated a continuous bad effect will bring more sins to the initiator of it, like the wrong sects or wrong ideas initiated by people who wanted their sin to be followed by others and has been followed already, so more sins with more followings of the original sin. The family of such sinner should do their best to stop the bad effect of that sin. For example, if the sinner had established an alcohol factory, or a place for committing sinful acts. If the original sinner told people wrong things about Allah, The Prophet or Ahlulbayt, the family should rectify and tell people not to follow the wrong statements, to see that the bad effect has been terminated. As good deeds which have continuous benefit cause continuous rewards, bad deeds which have continuous bad effects have continuous punishment. If the deceased took the right, did wrong or harmed others , his family should return the rights of others to them and seek their pardon for the deceased, so that the wrong deed initiated by the deceased is terminated and it's bad effect is been washed away.

Wassalam