Kate,
As we always say about Health Depts...doesn't matter what we think, it matters what they require, so you might have to ask.
Keep them from looking in an empty smoker, just keep it hot and full of food and they can't see the back wall
I don't think the health dept will care about seasoning, in a smoker, but just look for the big, loose and obvious food that is sticking inside and get rid of that.
The smoker is seasoned, and just like a cast iron, you won't "clear" the walls. What I try to do is keep the chunks from building up. A simple putty knife keeps that clean. Don't worry about any areas you scrap off, the next smoke will take care of it. Every couple of years, I clean my CS's real good and then I just re-season.
And I never use any cleaner inside my smoker that isn't food safe. When you heat 409 up, it doesn't make the food smell great.