With Mary, the most Holy Mother of God. In the book, Glories of Mary, St. Alphonsus teaches that a prayer to any saint is vain if it doesn’t involve the consent of the Blessed Virgin Mary. That would be the answer to how efficient is the asking of the intercession of a saint.
“invite everyone to become a trusting child before Mary, even as the Son of God did. Saint Bernard says, and we say with him: ‘Look to the star of the sea, call upon Mary … in danger, in distress, in doubt, think of Mary, call upon Mary. May her name never be far from your lips, or far from your heart … If you follow her, you will not stray; if you pray to her, you will not despair; if you turn your thoughts to her, you will not err. If she holds you, you will not fall; if she protects you, you need not fear; if she is your guide, you will not tire; if she is gracious to you, you will surely reach your destination”’ (Benedict XVI, address at Heiligenkreuz Abbey, September 9, 2007)