Shlissel Challah

Q: Is there an authentic source for making Challah with a key in it (or in the shape of a key) on the Shabbat after Pesach as a Segulah for Parnasah, or is it superstition?
A: It is not forbidden but there is no meaning in doing so (this custom is mentioned in Ta'amei Ha-Minhagim pp. 249-250).