Soak the breather with kerosene or Diesel fuel, place it in a safe area, and light it off. The sludge will burn away to ash, which can be tapped out with light blows from a hammer. It won't hurt the metal of the breather at all and it's a lot quicker than trying to scrub or pressure wash it.
Jerry.

"It is better to be silent and be thought a fool than to speak and eliminate all doubt!" - Abraham Lincoln
Cringe and wail in fear, Eloi- - - - -we Morlocks are on the hunt!
There is nothing noble in being superior to your fellow man; true nobility is being superior to your former self. - Ernest Hemingway
Love your enemies and drive 'em nuts!