Aha... -classic!
Someone refers to "Flux Capacitance" and not even the slightest hint of a "Doc Brown" Back to the Future reference!!!
In actual fact, you have to clean it all off, in case it causes a time paradox, the consequences of which could be disastrous...
Great Scott!!!
:green:
Okay, "back to the subject" -in high impedance circuits, well, conceivably, but I bet dollars to doughnuts that you can't hear it. A rather more practical reason might be that some fluxes can be corrosive, so it's a decent idea to clean it off anyway. The kind of person who says they can hear the difference in most circuits is probably the kind of person who buys cable-cradles for their speaker wire.
For real.
Keith