I see what your saying, but aerosols (atom size and smaller) would be dispersed to insignificance and soon blown past our orbit. They would be more akin to CMEs which consist of much more mass than ISON has. Now a large dust cloud (with micron and larger sized particles) that earth had to traverse for hours or days could be a different matter.
The speculation is as well that as this debris free floats it will cause a light show not unlike that of an Aurora that we were speaking of last night.
While this is still speculation since we won't know till mid-november if it will have an outbound path.
I must say though I do not subscribe to the tin foil associated with this comet there is some really cool aspects not realized before in science associated with this particular style of heavenly body....lol