After couple of years, using the WSM I smoked non-stop for 30 hours.The build up on my lid is causing it to stick to the mid cylinder part of the smoker, very difficult to break apart. Even after remaining apart in 30 degree weather for two days, I closed it up and when I tried to take it apart hour or two later......stuck again. The build up looks like a thick coat of grease or syrup. Can this be cleaned? Any suggestions? Thanks!