It is said in the name of Reb Mendel M'Riminov that saying Parshas Ha'monn (Shneyim Mikroh V'Echod Targum) on Tuesday Parshas B'Shalach, is a Segulah for Parnasah. Does anyone know a source for this "Minhag"?
According to R. Amnon Bazak, there is no source, and it in fact goes against tradition. Although the custom to recite "Parshat ha-Man" appears in the first siman of Shulchan Aruch, there it is a practice for every day, "in order that one should believe that his food comes with divine providence." This practice was not widely accepted.
Some poskim quote a midrash (whose source is not otherwise known) according to which one who recites Parshat ha-Man every day is guaranteed not to lose his food supply. Those who promote saying Parshat ha-Man on Tuesday of Beshalach claim that it is based on R. Mendel of Rimanov, who did dedicate much of his teaching to Parshat ha-Man. However, this segulah is not mentioned in any of his seforim, nor in any other sefer of Torah literature. Instead of searching for segulot, we would do better to heed the words of the Torah:
"וְהָיָה אִם שָׁמֹעַ תִּשְׁמְעוּ אֶל מִצְוֹתַי אֲשֶׁר אָנֹכִי מְצַוֶּה אֶתְכֶם הַיּוֹם לְאַהֲבָה אֶת ה' אֱלֹהֵיכֶם וּלְעָבְדוֹ בְּכָל לְבַבְכֶם וּבְכָל נַפְשְׁכֶם. וְנָתַתִּי מְטַר אַרְצְכֶם בְּעִתּוֹ יוֹרֶה וּמַלְקוֹשׁ וְאָסַפְתָּ דְגָנֶךָ וְתִירֹשְׁךָ וְיִצְהָרֶךָ. וְנָתַתִּי עֵשֶׂב בְּשָׂדְךָ לִבְהֶמְתֶּךָ וְאָכַלְתָּ וְשָׂבָעְתָּ".