I really thought I'd addressed this issue before, but, looking back over this thread I can't find my post. Possibly it was on some other post - so apologies if I'm repeating myself here....
A few years back I came across a very interesting blogpost called, I think, I Was A Black Eyed Kid (or maybe even I Was A Teenage Black-Eyed Kid). This had a take on the phenomenon that I have not seen aired elsewhere with the same depth. The trouble is, I haven't been able to find the post again and don't recall where it was posted - but trust me it does exist (or did exist).
So I'll try to summarise his main points, but it won't have the detail that he was able to offer.
Essentially trhere is an unnamed youth culture out there which takes its inspiration from Anime comics, cosplay and maybe something like Emo. It is mostly concerned with dress rather than music. The devotees of it like to dress up in the apparel of their heroes - and this usually involves Victorian style garb.
Its followers are `tweenies` more than teens - that is of the 12/13/14 year old age group, rather than older. (Wearing my teacher's hat, I can confirm that Anime has a lot of hold over many kids of this age bracket).
Their drug of choice is called, as far as I can remember, Cherrybombs (yeah, just like the poster). This is an amphetamine based stimulant which has the side-effect of dilating one's pupils. Also it flattens emotional expressiveness and makes one want to go to the toilet.
(Can you see where this is going already?)
Another important aspect of it is that it is a middle-class subculture. Nowadays this means that most of its adherents live in semi-rural and rural type areas (you don't often hear of Black Eyed Kid encounters in central Wolverhampton, do you?)
This subculture has been going from at least the early noughties, but very few people over the age of thirty know anything about it.
So taking all that into account: one could easily envisage a situation where a group of very young looking kids, dressed in apparently archaic clothing, are wandering around in a semi-rural location complete with dilated pupils. They may stop at houses and, with a jittery manner and monotone style of speech, may ask to enter the home (to access the bathroom).
As far as I'm concerned, this information puts the who;le thing to bed.