I remember trying to get bird poo off a window, when trad,
i was rubbing away with the end of my applicator, when i suddenly noticed a long mark on the window
that i could not shift, that was not there before, ... looked at the end of my applicater, and the plastic bar
was poking out the end of a hole  
  lets just say for the next year of cleaning his windows, before he moved, i could not get rid of that long mark
 off the  glass,    
