It would be interesting to see a basically adult killer Eiko as their enemy in future chapters either alive or as a ghostI wonder if author is planning to keep the identity of that serial killer unknown to readers... It was portrayed kind of irrelevant to granny's grudge (it's more or less directed at shinigamis).
All hes missing is a cane to push the souls out withWhy that man give off Urahara vibes??
The author's post-chapter notes refer to it as a type of plant fertilizer (you can see her using it as intended on page 28) but when I was first reading I assumed they might've been naphthalene balls (which would've been used back then to throw in stored clothes to prevent moth and mold infestations and serve as a general pesticide, human consumption of it in notable quantity would destroy blood cells and cause hemorrhages in the eyes and face).So... the balls she's chewing on are poison I guess?