I adapted a big stainless steel stock pot to one of the vibrator cleaners I use for polishing brass cartridge cases for reloading. A strong solution of Trisodium Phosphate (concrete cleaner) and hot water, and several hours of shaking in the cleaning solution softens the crud in the passageways. Then a massive amount of high pressure air from a needle-tipped blow gun through every passage blows them clean.
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!