That dustoff stuff is probably hydro-bromo-choloro-fluoro-metzo-piano-carbons, and does a lot of damage to the Bozone slayer.

I'd think some CLR or dilute muriatic acid sprayed into the system, to dissolve the calcium scale. But, I'm probably out inspace.
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Christopher A. Young
Learn more about Jesus
www.lds.org
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"Retired" wrote in message ...

Consider trying to blow the tubes/hub clear with a can of compressed
air. Office supply stores (Staples, Office Depot etc) sell them for
cleaning computers, printers, etc.