Schlissel Challah

Hey, everyone. I'm back, from undisclosed locations. Which could be anywhere from Alaska, to my in-laws house, to my very own kitchen. Not telling. But it was great, wherever we spent it. Hope you all enjoyed your Chag as well.

I have already moved on today to the post-Pesach activity of baking "Schlissel Challah". I am no expert on the custom, which was handed down to me by my Mom and her mother, but you take a key, and bake it into a challah. As far as I always heard it, using the challah for Lechem Mishnah at the Shabbos table the week after Pesach is a Segulah for livelihoood. I was told that it does not matter whether the key opens any particular door, though I have heard that some have the custom to use the particular key that opens their own front door.

Another few explanations for the custom that I found here:

1. Based on "Pitchi Li Achoti, Ra'ayati..." ("Open up, my
darling..."--Shir HaShirim 5:2), on which the Medrash states "Pitchu li
petach ke-chudo shel machat...," (cf. Shi HaShirim Rabbah 5, s.v. "Kol
Dodi Dofek") = something like "Open your hearts (in teshuvah) like the
eye of the needle, and I (God) will open the rest like [a very large
opening].

2. According to Kabbalah on Pesach the gates to heaven were open, and
following Pesach the lower gates are shut, and it's up to us to open
them again, therefor on the 1st Shabbat we put the key on the challah to
show that through the mitzvah of Shabbat we are opening the locks
[original source?].

3. In the desert the Jewish people ate from the manna until after Pesach
upon entering the land (with the bringing of the Omer, see: Josh. 5:11),
at which point the ate from the produce of the land, and became
dependant on their livelihood for the first time (now they had no
manna). The key in the challah after Pesach is a request the God should
open the Sha'arei Parnasah (gates of livelihood). Alternatively, the
manna began to fall in the month of Iyyar, and this Shabbat is always
Shabbat Mevarchim Iyyar.

See: Sefer Ta'amei HaMinhagim, pp. 249-50.
See: Encyclopedia Judaica, vol. 6, pp. 1419-20 for a photo of a shluss
challah (and other "special" challot). It seems (from both of the above
sources) that the minhag was to bake the key on top of the challah not
inside (a la the old jail break trick).

Anyone else baked Schlissel Challah today? Anyone else have any good sources for the Minhag?