my owb is done running for the summer. i cleaned out all the ash and swept the chimney. do i need to clean the layer of creosote/tar from the firebox?? i scraped and scraped, but it is pretty tough. i'm guessing this will protect the metal. i leave the blower fan run to create a draft in the summer time so humidity/condensation dosn't build up. i noticed that when i do this, i have no humidity/moisture in the unit at all during the summer. from what i was told, i should just worry about keeping it clean of ash. any suggestions are welcome.