There are two privileges granted to the scapular wearer. The Sabbatine privilege is the second one.
The main promise of the Scapular is preservation from the eternal fire. This comes from wearing the scapular, and I do believe, practicing a devotion to Mary.
Carmelnet.org has the rules and regulations:
This is probably the most important one. Note, I have seen conflicting evidence on this, but I tend to go with this.
Other sites will tell you that the special devotion you must practice is “the Little Office of Our Lady” which can be “commuted by any priest to a rosary.”
The reason why I disagree with the EWTN link (the second link) and agree with the first is t
his Fr. William Most article, my tie-breaker, and besides,
Carmelnet.org is actually carmelite, so I suppose they know what they are talking about.
Anyway, Fr. sets up some persuasive reasoning. He asks, what is necessary to gain this great promise of our Lady’s (that is, protection from eternal fire)?
Code:
Hence, why I reject the contrary reasoning about supposedly needing to recite the Little Office of Our Lady or a Rosary as the special devotion. My reasoning goes further, though. I can assign a reason why they err in saying the Little Office or Rosary for the Scapular-- and that is because such things are required for the Sabbatine privilege.
Fr. Most is most illustrative once again:
So, the Sabbatine privilege is the second (alleged) privilege of the Brown Scapular, which consists of being released from purgatory the Saturday after one’s death.
Note Fr. Most’s qualifications about it, and also the fact that it is absent from the
Carmelnet.org website.
However, as you can see, as I bolded it, the Sabbatine privilege requires saying the Little Office, or a Rosary if commuted.