I tend to do this after each and every smoke on my woodwind. I will scrub them with soap and hot water. I see many videos where people are demonstrating their smokers and it does not look like that is a common practice. How often do you all clean your grates, other than just with a wire brush, or do you? On my Weber propane grill, I will just hit it with a wire brush both after and before a cook, but my temps are typically around 400 - 450.