The best practice for logs to saw is just keep them out of the dirt. A 3 point system on a tractor, and a chain or choker to be able to lift the butt end well off the ground is ideal. Makes skidding far more efficient too. A log arch will do the same, and actually predates modern equipment. That way only the far end of the log may be dirty, and you can knock that off with an axe, only the entry cut matters, then the rest is eliminated with squaring the cant.
If far enough north, skidding logs on snow, or at least frozen ground is best, logs can be completely dirt free.
The technical solution is to use a circular saw leading the cut to make a clean kerf. But clean logs are better for all the equipment and steps of processing later on. If sawing lumber for others, running into dirty logs is a certainty.