I am finding it difficult to clean the glass on my quadrafire 7100.My wood is not as seasoned as I wish it was but just got the fireplace a month or so ago so I found as dry of wood as I could.After a slow burn at night the glass is pretty black.Been using glass cleaner on a paper towel dipped in ash. It does finally come clean but takes forever and allot of scrubbing.What do you guys use?