There are two very easy ways to debunk outrageous cable, "power conditioner", "isolator", "speaker cable suspender", "special capacitor", and "special resistor" claims:
1) Measure the electrical and acoustical signals with the allegedly improved "product" versus without. It's the year 2018 folks. We now have cheap devices that detect all aspects of sound (phase, pressure, frequency) at a level that is orders of magnitude better than average human hearing. What once cost tens of thousands of dollars in testing equipment can practically be obtained for several hundred with a high performance laptop, high quality calibrated microphone, and audio test suite freeware.
2) Research the backgrounds of the individuals who own and run the companies that are peddling "special resistors", "speaker cable suspenders" and the like. I've been observing this scam for nearly 4 decades and every single "manufacturer" of said products I've looked into is run by con artists and fast talking salesmen/women. Just like there are tons of con artists peddling miracle health cures, there are and unfortunately probably always will be con artists selling magic cables and capacitors that some how fix everything that is wrong with your audiofool system.