I've used it for 20 years and have not ever had it scratch glass.Thanks alot for the info guys. I guess my only concern is dors it diminish the quality of the coatings already on the glass.
Whoa! Thanks for the advice!!I have been using it with good results. However, on a recent moose hunt I am damn glad I had a lens cloth handy in my bino pouch. We had been sitting on a good bull waiting for a shot opportunity for a few hours in a wet snow storm. Seconds before he steps into an opening my scope had finally fogged from being wet in the snow! I had been checking it for hours and it was fine and then it fogged. I was freaking out and thank god I had a lens cloth handy to clear the fog off the lenses. I guess the point is, while the cat crap may help, you darned better have a lens cloth handy!