Tuning Collars on speaker cables - concept and any good?

I’ve had those purple Shun Mook Original Cable Jackets and the spiral Cable Wrap, both of which were purported to absorb “reflected signal” in the cable. Both of those devices worked well (when correctly positioned) so the concept seems to be valid.

Back in the day; I always installed ferrite beads, on what I considered applicable wiring, within the components I built or upgraded.     Is there a correlation?      If so; it’s well-established technology, in some applications.

Just a big sham dude.

That's what I used to think. Then I had an actual symphony conductor over for dinner one night. After drinks he suggested some Stravinsky. Right away he jumps up stop stop STOP! Walks over to the tuning collars, slides them about a half an inch, sits back down, raises his arms in that way- you know one a littler higher than the other- and I cue the arm back down. 

Sure enough, we were sharp, now it was in tune. So they totally work.

Yes some people love to play with new audio toys, especially fancy or esoteric  expensive ones and strain to hear or convince themselves of some meaningful difference so lots of merit there