If yukkuri are based on a system of belief, then wouldn't it have been simpler to simply believe she's not scum?
Nope, after all they don't see themselves as scum even if they are scum, so it's pointless, it's like some sort of programming RNG that decides who is born as scum, shithead, nice, average, etc. Yukkuris after all are magical pastry golems.
THAT'S ALL!SCUM!IS SCUM FROM THE MOMENT IT'S BORN!