It likely doesn't go in the whole wall, more like in a small container friction fit between tiles. That way you can empty it once it's full (not too soon, admittedly)
Edit: there was a comment here about two feet of blades, so I was wrong, it does go into the wall and it is a 'fuck the future me' kind of thing ๐
They are very slim. You would really need to shave a lot to see it being full.
But when that happens, who's going to want to remove a wall full of used razor blades?
It likely doesn't go in the whole wall, more like in a small container friction fit between tiles. That way you can empty it once it's full (not too soon, admittedly)
Edit: there was a comment here about two feet of blades, so I was wrong, it does go into the wall and it is a 'fuck the future me' kind of thing ๐