This is from Fr. Paul O'Sullivan in his work "How to Avoid Purgatory"
Among the extraordinary graces which Catholics gain by becoming members of a Third Order is a share in many Masses and prayers. To mention, for instance, the Third Order of Saint Dominic, Pope Benedict XV, himself a Tertiary, said: “One of the easiest and most effectual ways of reaching a high degree of sanctity is by becoming a Dominican Tertiary.”
The members of this order receive during life a share every day in thousands of Masses and prayers, and after death, when, alas, so many are neglected by their relatives, those who are members of this Third Order have a share daily in thousands of other Masses and prayers, this for as long as they remain in Purgatory! Among the many beautiful characteristics of the Order of St. Dominic is its intense devotion and love for the Holy Souls, especially for the souls of its members, friends and benefactors. So true is this that a young Italian nobleman who consulted the Pope as to which religious order he would do well to enter received for answer: “My dear son, you may with much profit join any of the Orders, for in each you will find abundant means of becoming a Saint. After death, however, be a Dominican” The Holy Father meant to imply that the suffrages given after death to their deceased members are, indeed, most abundant in the Dominican Order.
The conditions of becoming a member of this order are so easy and the advantages so many that half the world would become Dominican Tertiaries did they know these advantages.Image Source: www.dominicansavrille.us