Catholic Culture has an excellent piece on the Catholic practice of indulgences and praying for the dead:
Included is an explanation for a devotion that I’ve written about previously, that of visiting a cemetery and praying for the holy souls in Purgatory during the first eight days of November:
Indulgenced Acts for the Poor Souls: A partial indulgence can be obtained by devoutly visiting a cemetery and praying for the departed, even if the prayer is only mental. One can gain a plenary indulgence visiting a cemetery each day between November 1 and November 8. These indulgences are applicable only to the Souls in Purgatory. A plenary indulgence, again applicable only the Souls in Purgatory, is also granted when the faithful piously visit a church or a public oratory on November 2. In visiting the church or oratory, it is required, that one Our Father and the Creed be recited.
Praying for the dead is a spiritual work of mercy. The dead have no recourse to their own prayers, they are entirely dependent upon our charity. The time of their own merit (life) is over. Our prayers for them, as well as the offering up of our earthly sufferings, trials and tribulations, assists in easing their progression through Purgatory.Know someone, perhaps yourself, who might like Catholic devotionals for alcoholics? Please take a look at my books! (Thank you!!)"The Stations of the Cross for Alcoholics"