A segula is a mitzvah. Ask the Rebbe for one and you are given the three daily shiurim, a checked mezuzah, charity before candle-lighting — the intercession (“I will mention it at the resting place”) always coupled to a demand that you add in Torah and mitzvos. Where the occult is reached for, he denies the frame entirely, applying the same “divert the mind” instrument found in the faith and health letters.
The intercession is real and constant — he will mention the person at his father-in-law's resting place — but it almost never travels alone. It is coupled to a demand: add in Torah, fix the mezuzos, give tzedakah. The "segula" he hands back is a mitzvah. And when a letter has already gone looking for a palm-reader or a cure for "demons," he does not negotiate with it.
How a request for help is answered, by how often each channel surfaces.
The move that defines the thread: asked for a סגולה, he answers with the three daily shiurim (Chumash · Tehillim · Tanya), a checked mezuzah, tzedakah before candle-lighting — "a segula for many things." The protection sought is converted into an obligation kept.
When a letter has already consulted a palmist, blamed a misfortune on demons, or feared sorcery, he does not debate the claim on its own terms. He denies the frame outright — the occult has no power, one is not meant to know the future — and applies the same instrument he uses against melancholy and doubt: hesech hada'as, divert the mind, don't wrestle it. Here, verbatim.