If I happen to have the saw apart for something, such as pulling the chain off, I'll usually scrape off the worst of it. If I've got the air nozzle handy I might blow it out. Other than that, I don't get any more fussy with them. They stay pretty clean though. I suspect alot of the nasty **** that we see is from a mix of dull chain and engine oil for bar oil. Worst one I had come in had been used to cut up a moose several months before and hasn't been cleaned out very well. Must have had it in a shed or something, cause it didn't stink till it sat in the shop a bit and started thawing out.