So this weekend I had to clean the inside glass on our fireplace. It was really nasty and I went over it 3 times with windex and even tried a kitchen scrubber. No dice. I went out to the garage to get something else to try and decided to give the Adams glass cleaner a shot. I assumed since it's for car glass it wouldn't be as strong as windex and would be a waste of paper towels. But the second I sprayed it on it cut right through everything! I wiped it ONE time and it was clean, hell, it looked brand new. Reminded me of those old oven cleaner commercials. I don't know what's in this stuff but count me impressed!