Does a blanket request for forgiveness effect teshuva?

Question

As Yom Kippur approaches each year, I often see people in leadership positions make blanket requests like "if I have hurt any of you this year, I ask that you forgive me". Are these requests in any way effective when it comes to doing teshuva? It seems that according to Yoma 87 and the Rambam (somewhere), we need to acknowledge the transgression and make amends, which is hard to do without knowing what it is and whom you wronged. On the other hand, respected, knowledgable people like rabbis and teachers in yeshiva do this, so they presumably know something I don't.

(When I've been in this position I usually instead say "if I have hurt you, please bring it to my attention so I can make amends", which would seem to solve the problem. But maybe I'm solving a problem I don't need to solve, and by instead making a blanket request I can do teshuva for transgressions that people would be too shy to make me aware of? This is not a request for p'sak, of course; that's just context.)

Answer 1

Mishnah Brurah 606 s.k. 3 writes:

ומי שהוא מבקש מחילה מרבים בכלל אינו יוצא אם יודע שעשה לאיזה יחיד בפרט

One who asks forgiveness from the public does not fulfill his obligation if he knows that he wronged a particular individual.

So it seems that there is such a thing as a blanket request for forgiveness, but only if the one asking doesn't recall specific wrongdoing, which can often be the case in the examples you mentioned. For instance, a Rabbi is involved in the private lives of many people and may not be aware of or remember hurting someone's feelings, so he makes a blanket request just in case.