Is the Holla Kreisch supposed to be something we're familiar with? I've never heard of it before.
The more esoteric the better, hm? It's a German Jewish custom. I once wrote about it, here.
Holla Kreisch = Kwaanza.
In shorshei minhag ashkenaz rav hamburger seems to indicate that holle kreisch was for boys as much as it was for girls, and this was where the kids were given their German secular first names.