Your favorite OCC speaker cable

@hilde45, another alternative could be Furutech’s FS-alpha, a discontinued product that could be found at very reasonable pricing. The successor is FS-a36, still OCC. 

What about PCOCC vs OCC? Real or merely a marketing ploy? Does that claimed super purity actually exist, and if so, does it make a difference?

The "PC" just stands for pure copper pre-pended to OCC, and possibly different source providers of the copper itself. A 6moons article for reference, and who knows where the real story originated or what is true. The conductor is part of the design, not all of it. Designs, dielectrics, connector ends vary from one mfg to the next. Demo & listen if you can!    

Clip;

"For many years the copper wire used in Oyaide cables was supplied by Furukawa famed for their PCOCC copper. That stands for pure copper Ohno continuous cast. It’s a method developed in 1986 by Dr. Atsumi Ohno at the Chiba Institute."...

https://6moons.com/audioreviews2/oyaide/1.html

Furukawa stopped manufacturing PCOCC some years ago, so Furutech, Acoustic Revive Oyaide, Acrolink, are now using PC Triple C or OCC-DUCC for their better products.
Both are more advanced methods in metallurgy than PCOCC.

OCC is from my experience a much improved wire over OFC, and over the years I have exchanged from OFC to OCC in Copper and Silver on most IC's.
I use Mapleshade Speaker Cable and can't vouch if this is a OCC Wire.

In recent months I have commenced with trials on PC Triple C and D.U.C.C Wire.
At present the PC Triple C Wire is remaining in the positions I have used it, and when attached to other devices there is noticeable changes, that I am coming to terms with.
I need more PC Triple C cables to fully understand the overall benefits throughout the system.