Are Shakti Stones effective?


I have never used Shakti Stones and wonder if they really work and, if so, what do they do,  I have used the Shakti Holographs and found them to magically focus the sound and tighten the soundstage. From what I have heard, even from Shakti, is that the stones make a significant difference is some usage and less in other. Has anyone used these and what do they do?
mglik
For me, they work. Significantly.  I place them vertically on my 2A3 tube amps between the power and output transformers. Everywhere else (DAC, SS amp, preamp, transport, music server) not at all.

Those are the only tweaks I use.
I have used them to great effect with CD/SACD PLAYER (over the transport and Power supply), and also on the amplifier CODA CSX (over the toroidal transformer). The presentation became more open, relaxed and the noise floor was lowered to an inky black. YMMV. 
I purchased a Shakti stone last year. It’s effect was immediately apparent and 100% repeatable on each piece of equipment I placed it on including the main breaker panel in my house. As the instructions stated the effect of the stone depends on its orientation on each component. If you don’t hear a change in sound rotate the stone 90 degrees, again, the effect was 100% repeatable each time. As for the sound, it produced a darker background and made the soundstage bigger. However, the larger soundstage was ‘artificial’, instruments went from sounding life size to being too large, the singers voice was exaggerated so their mouth was like a foot wide. I liken it to increasing the size of a picture in MSpaint, when you stretch it out it becomes larger but all the pixels become blocky. I did not find it pleasing in my system due to the exaggerated, no longer life size scale of the music. Perhaps a different system could benefit from the use of a shakti stone. 
mglik Are Shakti Stones effective?

About as effective as Shun Mook Pucks, Geoff Kiat’s Pebbles (https://www.machinadynamica.com/mikro-pebbles.jpg), $150 Boutique Fuses, HFT’s and a host of other snake oil products, that convince the gullible to hand over their cash.

Cheers George