You can expect that in many cases there is going to be a lot of various fluids, much more than you would normally find on the sidewalk, that are left behind. A lot will depend upon if the remains are in one piece or are hundreds of shreds spread over a long distance. The coroner only picks up the larger pieces. The rest are left behind. In some places that might not be a good idea, so a special cleaning contractor is brought in. That is going to take a lot longer.