A Nikko Alpha III poweramp that I previously owned made a "kaboooom" sound every time the fridge turned on, if playing very loud this could be to the point that it could be a danger to the speakers, I'm not sure about this but nothing bad ever happened. At that time I did not use any power filtering mechanisms, but it clearly shows that there is unwanted residue on the power lines. How much and how it affects sound I cannot vouch for but it surely is a need to remove these things.
I never had a possibility to check this further as this amp is long gone by now and my current equipment never showed any of these things.
Probably a decent professional power surge protector will keep these things away, a $21k power cable will definitely not make any difference to this situation.
Perhaps I should have changed the power cable of the fridge to a Nordost power cable