It isn't empty, although it has a very low particle density. I assumed that 'clearing out' means the opposite, that the area now had a higher than normal charg

It isn't empty, although it has a very low particle density. I assumed that 'clearing out' means the opposite, that the area now had a higher than normal charged particle density, and thus it was easier to pass through? I'm also curious if anyone can give a thorough explanation.