These rituals are performed for several reasons.
1. It is a way of paying homage and remaining connected to the family roots.
2. From the occult point of view they might help in clearing the earth atmosphere a little bit from the presence of several tiny elemental energies released from the dead that float in the atmosphere. But there are better and higher ways of doing this. For example a Yogi by his mere presence brings the play of benevolent energies in the surrounding environment that do the same thing. The sound of conch shell and bell as in evening prayer rituals, the incense fragrance, lamps, all of them do the same. It is just that the process becomes easier during certain phases and when done as part of the collective observance.
Affectionately,
Alok Da
