In the year 1251, in the town of Aylesford in England, Our Lady appeared to St. Simon Stock, a Carmelite. She handed him a brown woolen scapular and said, This shall be a privilege for you and all Carmelites, that anyone dying in this habit shall not suffer eternal fire. In time, the Church extended this magnificent privilege to all the laity who are willing to be invested in the Brown Scapular of the Carmelites and who perpetually wear it.
True devotion to the Blessed Virgin Mary consists in three things: VENERATION, CONFIDENCE AND LOVE. By simply wearing the Scapular, we can tell her every moment of the day that we venerate her, love her and trust in her protection.
Now contrast this with Deuteronomy 6:4-9
4Hear, O Israel! The LORD is our God, the LORD is one! 5You shall love the LORD your God with all your heart and with all your soul and with all your might. 6These words, which I am commanding you today, shall be on your heart. 7You shall teach them diligently to your sons and shall talk of them when you sit in your house and when you walk by the way and when you lie down and when you rise up. 8You shall bind them as a sign on your hand and they shall be as frontals on your forehead. 9You shall write them on the doorposts of your house and on your gates. Deut 6:4-9 NASB
There is no allowance for the "True Devotion" to Mary as taught by Roman Catholicism.
As noted before....the attempt to equate the false teaching of wearing the Scapular to keep you out of the hell fire is in contradiction of the NT. Further, the failed attempt to use the passage in Deuteronomy 6 to justify wearing the Scapular shows a lack of understanding of proper Biblical exegesis.
But addressing the brown scapular specifically, what you're quoting needs to be interpreted in context, as cautioned to Catholics who misunderstand the scapular here, specifically addressing the quote you cite: "This must not be understood superstitiously or magically, but in light of Catholic teaching that perseverance in faith, hope and love are required for salvation. The scapular is a powerful reminder of this Christian obligation and of Mary's promise to help those consecrated to her obtain the grace of final perseverance." To elaborate, the Catholic Church classifies the scapular as a sacramental. A sacramental does not convey the grace of a sacrament and does not have salvific power in itself. The priviledges mentioned in the quote you cited depend on the wearer remaining in a state of grace--remaining under the protection of the "shield of faith" from Ephesians. The scapular protects faith. It is a reminder to reinforce faith, which is how it is similar to the clothing accessories mentioned in the Deuteronomy passage I referenced.
As for proper Biblical exegesis, if I were doing exegesis, I would be reviewing the rabbinical rules for exegesis, diagramming sentence structures and key words in Hebrew, discussing the authorship and audience of the passage, considering the literary and historical context, reviewing the history of the interpretation of the passage in commentaries and scholarly articles, etc. Simply referencing a footnote is not doing exegesis.