My approach is as follows:
I never wash my WSMs ever. I only wipe the outside. I use wire brushes to scrape the insides, inside of door, and dome after each cook and reline the foil. For the grates, I put them in trash bag and then spray them with oven cleaner (use gloves please), and rinse them off. The way to tell a properly seasoned pit is to smell it. If it smells good, imagine how your meat will smell and taste if the pit already smells good before you start cooking. Again, you can do what you want but my strong recommendation is to NEVER wash your insides! Scraping will get all the gunk off. I use the $1.00 BBQ brushes on sale from the 99 cent store and discard them when they are clogged.
Also read my other posts about other no-no's for your competition WSMs: fish, hot dogs, lamb, hamburgers. If you don't use them for comps, you can ignore my advice.
Just my $0.02.