No ABX... just as described.
Listen to your setup at home, at will at your convenience whenever you feel like it.
Teach the person who will be helping how to change the cables.
They should change the cables at random days when you are not there.
They should keep notes with day and time of change.
It should NEVER be visible to you which cable is in there. Cover them with paper or something else if you can see them.
Ensure you don't KNOW.
Listen to the music at your own leasure. Make notes + day/time of which cable you can clearly hear is in there (add confidence level if you want)
After a month or so compare notes.
In my case the item (a 'tweak' that is supposed to work after a few hours and would make sound more 'real') was switched just 3 times simply because the wife forgot to do this after a while and the remainder of the days the tweak wasn't applied.
There was no correlation and at times I would swear the tweak was applied and other days not. Even when there apparently was no tweak.
I also had a pre-amp with a switch in the back (my subjective days long ago) in it I could switch between capacitor coupled (using electrolytic caps, a few of them in series and cheap TL071 opamps) and a DC coupled pre-amp with compound decoupling and OP27 opamps (the rage at that time)
I swear I was able to tell and so did others when I flipped the switch and told what was in circuit.
On 2 occasions I accidentally left the switch (not visible and not easy accessible) in an unexpected position.
I listened for months to the 'poor' quality pre-amp without knowing it, being sure I left it in the 'good' position.
Never heard bad sound and always sounded great. I was fooled.
Another time I was fooled because I remembered the switch position incorrectly.
Hadn't used it for years and when someone came over to hear the benefits of DC coupled good opamps I had given it a few switches and left it in the wrong position.
Result: when demonstrating and telling what was what I accidentally told him (and me) the reverse conditions. So when I said 'good' it was the poor one and vice versa.
Later we were both satisfied and clearly heard the 'good' one won.
The next day I had to change something in the back and realized I had it reversed. Never told the guy and that was one of the moments I started scratching my neck.
Later in life I worked at a high-end store which also sold cables of course. I was repair/service guy. When the usual install guy was on vacation I had to take over his work.
Sometimes this involved installing new cables.
At our shop one could always return cables when not satisfied. In all the years NO one EVER returned any cable !!!!
One of my 'experiments' on hifi addicts was described
here (scroll down to the bottom part)
yes, anecdotal but should make one wonder.