So, I don’t see how the video you posted would help a member test cables or other components.
I explained how you do that in the video. Setup your system such that you don't know which cable is used (cover/hide it). Then have a loved one randomly switch one cable for the other. You keep score of which is which as does the person doing the switching for you. Do this 10 times and see if you can correctly identify one cable at least 8 times. Seeing how in sighted tests major fidelity changes are reported, then this process should back that up. If not, then the sighted tests are faulty.
If you are unwilling or unable to do such tests, then my measurements and null tests are an excellent substitute. In some cases I have actually provided the captured outputs of the system so you can use any ABX software tool to compare them.
So very easy to do when it comes to cables (or any other audio tweak) which is the topic of this thread.