Has anybody tried using single solid core cables?

At a recent hi-fi show an exhibitor auditioning $47K speakers repeatedly asserted the following: "Any solid core wire, even $0.03 a foot is better than any multi-strand available. Experiment for yourselves, you will be amazed."

My question before I ditch my multi-stranded Audioquest Indigo cables in favor of 4 individual single solid core 18 gauge cobber cables from Home Depot for my newly acquired SA Mantra 50s, has anyone tried using single solid core wires?

I like AQ a lot and am thinking of getting another pair for my Thiel 2.7's Which ones are you using? I have had the Rocket 33 and Rocket 88's with DBS. Thinking of getting another pair of 33's.
After many years of trying every brand and geometry of cable within reason. I have always found myself settling with solidcore cables. Generally they always seemed to sound more focused and direct sonically.

I like the AQ DBS cables I have tried, but they seem to focus more on treble extension and speed. I just find they don't do timbre and 3D depth so well when compared to others. A little solidstate sounding if you know what I mean?

I too have ended up with DNM after many exotic cables (analysis plus golden oval/AQ WBY/ Virtual dynamics Genisis/Kimber Black pearl/ etc) Although I do like MIT cables very much for their 3D depth.
Hmmm, Wonder if DNM would be a good match with my Thiels?? I will look into them as well as the Rocket 33's.
Wolf, which IC's do you have, what do you think of the Big Sur or the Syndey interconnects from Audioquest?