Speaking of maintaining...I will now completely clean my kettles after each use. Yes, completely! Not going to spend days and days scraping carbon again.
Look at it like a set of pots and pans. Everyone washes them after each use. We even clean our kitchen gas range after each cook. My kettles deserve the same attention!
I like to keep most of mine clean, but I have a couple of work horses that are well seasoned and really turn out some great BBQ flavors I think due to that. The well seasoned ones are not allowed in the house - keep them covered outside and ready for action.
My offset firebox smoker is well seasoned. I clean it, but not often.
My Cooker has been abused and neglected over the decades, actually sitting out side all winter long. I won't make that mistake again. It looks amazingly good considering the torture it's taken.
My two real Weber's are parked in the garage, alongside my Weber Wanabee (Happy Cooker). I don't think my wife would allow grills in the house, mainly due to the BBQ smoke odor they have. My smoker has an awesome pecan / mesquite aroma!