What is the science behind audiophile fuses?

There were many threads on the topic of "audiophile fuses" on this forum, and I sure don't want to open old wounds and trench warfare. The fuse on my preamp blew suddenly two days ago, which prompted me to search for a replacement. That's when I came across the term "audiophile fuse" and the fact that they demand far-out prices. Deeper curiosity brought me to several other fora, where users posted glowing praises about their Zero fuses and other exotica. Now I am a scientist, but not a physicist or electrical engineer: so please enlighten me! How can a fuse have an audible influence on the signal, when the signal does not even pass through it? How can a fuse be "directional" when it deals with alternate current? I mean, if I recall my university physics, a fuse is basically a safety valve and nothing more. Am I completely missing an important point here? My scientific field is drug discovery, and because of this background I am thoroughly familiar with the power and reality of the placebo effect. I that's what I am seeing here, or is it real physics? I need objective facts and not opinions, please. I really appreciate your help!