After each cook in my Yoder traditional offset smoker with the heat management plate, I clean it while it is still warm. That way, it is still easier, to remove food debris, and grease drippings. I scrape the two grills, and remove them. Then I scrape the heat management plate of the crust and and burnt stuff till it is clean and smooth again. Then I remove the heat management plate and do the other side. With the main grill empty, I take my scraper and scrape the entire interior of the main smoking area. I remove all debris and rub it clean with paper towels.
I, then, re-install everything inside the main unit. The next day, after everything has cooled down, I clean the firebox completely and remove all of the ashes and place them in a safe metal container.
Once in a while, I take my blow torch and hit specific areas that have a little build up until it is clean. In order to remove a grease stain, I use a product called Citra-Solve which ok for food and that takes care of things like that.
I have not tried the steam clean approach yet, but that sounds like it might be worth a try. The only concern that I have about that process is that I really did a good job on seasoning this smoker with a heavy coat of peanut oil and I do not want to remove that coat of protection. Since I did the entire smoker with sponged on peanut oil in and out, I have no rust or any deterioration. As a matter of fact, I was planning to do that again as soon as we have some temperatures in the 80's again.
Ed