"Negative ion generators". Check out Thought Emporium. He managed to have some of them banned.

OK, those sound... dumb. Wow.

But there's nothing specifically Chinese about them, and they have nothing to do with moving house.

If a previous owner used one, they're probably going to take it with them, same as the rest of their stuff?

And it sounds like the powder form is used in bracelets and necklaces.

Specifically the bizarre pseudoscience ones, not the electrical ones used to electrostatically remove particulates from air (and sometimes add ozone into the bargain).

If anything it's impressive that the purveyors of such bracelets and other things would go to the bother of including radioactive material in the first place. They could have just put some ground quartz (i.e. sand) in it and said it was "crystals". No one was going to check, and even if they did, and you couldn't fob then off by saying their test was invalid, like the Batteriser guy tried to do, what would they do about it? Leave you a bad review on Amazon before you rebrand as Engrokoo or something and pop up as a new name?

I understand it may seem confusing. These ”energy healing devices” are a very real danger when people unknowingly order them online and their kids take them apart.