I suppose so... though I reckon the person's familiar could leave, in which case they'd be left here without access to any magic. Honestly, I have a feeling that the original intent was mostly along the lines of "Here's a neat method of ensuring the person you hate doesn't make it back to your world with you".

[One more reason to be glad Okita was sent home long ago - that shitty sadist definitely would have tried to get his hands on one of the daggers to make sure he can take Hijikata's position back home undisturbed.]

But there's no telling how it'll go in the end. Other worlds will hold nice ceremonies and send their heroes off with a return charm, but I wouldn't be shocked if the fae just kicked us out as abruptly as they teleported us to Celliwig that one time.