I haven't cleaned the glass in awhile and it had that white glaze build-up that doesn't burn off. Also, there are a few areas of the door that get black over time; I guess the air wash flow is lacking in the corners. With these warm days, I have not been burning overnight. This morning since the stove was cold, I cleaned out the ashes and decided to also clean the glass. I do use cleaners but I double rinse afterwards with plain water to remove any chemicals left behind. I have never had an issue with using glass cleaners using my double rinse with plain water afterwards. It is nice having a clear view to the fire for a change.