From Looking into the Sun by Rabbi Menachem Nissel published by Feldheim
Rav Moshe explained that segulos are not a magical shortcut. The avodah (hard work) for parnassa includes tefillah, maasim tovim, and working on emunah. If you've worked on these things, the heavenly shefa can come pouring down. 1he segulah can then be a vessel to contain them.
Rav Shlomo pressed on. "What did Rav Moshe think of the new custom where Ashkenazic men do pesichah (opening the Ark)when their wives are in their ninth month?" Rav Shlomo's greatgrandfather,Rav Shimon Schwab, did not approve of the custom. (Note: The custom is mentioned in the Chida, Avodas Hakodesh 1:90.)
Rav Moshe replied that pesichah all year round unleashes rachamim min haShamayim. However, to do so without kavanah and tefillah is a maaseh kof b'alma, nothing more than the actions of a monkey.
Not all my friends received such positive responses. When asked about the Yerushalmi segulah of going to the Kosel for forty days, Rav Moshe responded with, "Why can't you just daven?" When a close talmid suggested a certain segulah, Rav Moshe gave him a piercing look and said, "Why don't you just hang up a horseshoe?"