Simply clean the fireplace glass
Not with ash, gall soap or black tea. Easy to clean is the chimney disc with the glass scraper for the glass ceramic field.
With a mist-dampened kitchen crepe, wipe the glass, then the scraper is used.
Then again with a kitchen crepe to clean the rest away and the arbor is ready.
Nothing there with ash "dust particles", gall soap "lubricants". I prefer to drink black tea myself.
The glass scraper is a great help to me and the dirt is gone in the NU. Try it!