We have all been taught to rosin our bows in only one direction, ie, frog to tip. While this is the method that I use, I can think of no reason not to scrub it in both directions. Is there some reasoning behind this method, or is it just tradition? Is there a possibilty of damage by applying rosin in both directions? I have never been given a reason for this procedure, and was hoping that some of y'all might enlighten me.