I think he is talking about the silencer assembly that won't come apart on the SM250. I have the same question. How do you clean it?
Run a razor blade around the seam of the cap on the silencer, either bottom or top, doesn't matter. This will break the glue joint, and let you pull it apart. Once it's pulled apart remove the foam fill that is in there. You will get a very SMALL amount of noise from the silencer once removed, but it will also keep it from clogging up again.
Jonathan, can you snap some pics. I'm curious to see how dirty it is inside the silencer