On the Shabbos following Pesach, there is a custom of some to bake "Shlissel Challah" - challah with the design of a key, or challah with a real key actually baked into it. It is alleged to be a segulah for parnassah (sustenance).
There's a debate about the origins of this custom, with some claiming that it is rooted in Christian and/or pagan practices, while others defend it as having Jewish origins. Yet, unlike certain hyper-rationalists, I'm usually not so fervently opposed
to such things even if their origins are questionable. There's lots of things in Judaism that originated in
foreign cultures; but where something originated is less important than
what we've made of it.
But what about the very idea of such a segulah? While the rationalist Rishonim were obviously not into segulos, I'm not militantly against them. Segulos are often harmless placebos, and may also be time-honored tradition.
Yet in this case, however, I am a little more concerned, given the wider
context. In the ultra-Orthodox community, there is a prevalent message
that it is wrong and futile to engage in regular efforts to obtain parnassah (i.e. education, training and work). Chazal's directive that a person must teach his child a trade, i.e. to be financially self-sufficient, is widely ignored in charedi society. There is a real problem of people focusing on segulos instead of doing the necessary hishtadlus. And the segulah industry is rife with problems.
Instead of trying to get parnassah via an unproven and unlikely custom of unclear origins, why don't people try get it via a proven method ordered by Chazal themselves? The answer, of course, is that Chazal's way is much more difficult. But such is the way of the world. "By the sweat of your brow you shall eat bread" - not by the key in the challah.
(Regarding segulos in general, see my posts on The Ring Of Power and Manipulating with Mysticism for Money.)