There have been times I have asked questions about certain types of prayers or devotions and practices with special promises attached to them. Like very specific promises. I believe David has even gone so far as to tell me that those things are not "real Catholicism" and I do not have to believe these private devotions of which there may be some truth. Well I saw a prayer of St. Gertrude (a lot like the divine mercy prayer) printed and next to it it said that it had been revealed to her that everytime someone said this prayer 4,000 souls are released from purgatory.
Now is this something that the church actually does approve since she is made into a saint? I would put that in a category of the other devotions like burying a statue or saying a novena where it is possible something good may come of it and the prayer attached to it but we can not know for a guarantee what God has to do for us in response.
I find it hard to believe that we can know that a certain prayer definitely releases a certain amount of people from purgatory. I find it easy to believe a prayer can release a soul or many souls from purgatory. It is using it as a formula/promise that I find difficult.
Whether something is revealed to a saint or to a sinner, it remains a private revelation, and therefore it is not obligatory for anyone to believe it. I would not style any reasonable private revelation as “not real Catholicism,” but I would also tend not to accept it unconditionally until tested and approved by the Church, for it is known that even saints can be deceived.
I believe you are showing proper discernment in rejecting the “quantification” of prayer (“4,000 souls will be released from purgatory”) while accepting the general idea that prayer can help to release souls from purgatory.
