I just recently had to clean out my GOSM it had built up a lot of grease in the bottom and scraping it out wasn't good enough evidently because it caught on fire. Was no big thing but it got a good pressure washing and re-seasoned and all is well now
Make sure to keep the ashes cleaned out of your unit, moisture and ashes can cause rust.
I used to clean my little red bullet everytime I got finished smoking and after reading and gaining knowledge I found it isn't necessary to give your smoker a nice shiny cleaning every single time you use it. In fact I have noticed lots of people clean certain parts but let the main body smoke and season many times.
I clean my grates everytime but have just allowed the inner body to "season" and this has been 3 weeks and counting and works great!
Spring cleaning only let all that good juicy flavor sit the winter and scrape her out in the spring. I do clean the grates after every smoke, get her up to temp and spray with water and steam her clean.