I trawled through the first 30 pages of this thread this afternoon with some dismay because I thought I had put this to bed some time ago as mythical in the case of fuses.
Alas no, some hear differences, and it is unscientific to be dismissive of them, they involve perceptions as much as other scientifically based things.
There is no doubt that fuses do, as with other crude connections, oxidize, and they escape our attention for long periods.
In the 70s I used Belling-Lee coax plugs and sockets for connection using a 'Y' cable between my Quad 33 pre and Nelson Jones 10+10 class 'A' power amp. This illustrated to all visiting that polishing the plugs and sockets improved the sound considerably into Tannoy Gold Lancasters, and engineers laughed at this as 'silly engineering'.
For both my Hi-Fi and my studio I have home made distribution boards, seven on the Hi-Fi one and eleven on the studio one.
In the former I have used the 5A Duraplug type because it is much easier to get a good contact between a round pin hole, than a square pin and a square hole, in which a fraction of a degree of error from square results in an infinitely small contact area.
I have also doubled the flex, soldered it, and cut half round stainless steel tubes which go under the screws to prevent them cutting the 'blobbed' flex strands, and also increased the size of the screws from 6BA to 4BA.
De-oxit and pro-gold every five years.