I don't know. I'm an ex-JPLer but a programmer not a rocket scientist. I recall reading a science fiction story that used that idea as a plot twist. The space ship in the story was accidentally sent through a Lagrange point and the ship suddenly started getting pummeled with junk until they changed course to avoid it. The moral being what you don't know can kill you.
My guess is that there would be garbage there, the same as Jupiter captured asteroids as moons, but I'm neither a rocket scientist nor a mathematician.
And I haven't seen the calculations, so I'm just going with a gut impression; I trust others who know for sure will be able to fill us in....