I've used MMO as a fogging oil to treat sticky valve guides, etc, but never as a fuel stabilizer. The best penetrant for valve guide deposits is KROIL, in my decidedly biased opinion. "Your mileage may vary!"
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!