Speaking of the oil, I saw mention of a new headphone cable. It use an insulator that contains carbon to make it conductive. So a conductive insulator.
Before you laugh my favorite diy interconnect cable use an insulator that is conductive. Suspect there is something to the conductive insulators.
Sommer Cable has released single ended and balanced bulk cable with foamed PE and conductive insulators in the last few years. Easy to source in Europe, a little hard to find in the US. I have used the Sommer Cable SC Club Black Zilk and Red Zilk. Not tried the single ended cable.
The Red Zilk is my favorite. Might be psychological, it seems better than the Black Zilk and the more expensive Sommer Albedo and Carbokab.
The headphone cable I saw mention of is Kimber Carbon. Being a product and not a diy it is more expensive than the cobbled up cables I build.
The Kimber Carbon is 3,000.00. The bulk Sommer SC-Club Red Zilk is 3.53 a meter. I assume the Kimber Carbon is two meters or close so the cost difference is not that extreme. And there are connector and labor costs built into the Kimber headphone cable.
My suggestion is to buy the Kimber cable. If it delivers on sound quality order some bulk Sommer cable and build an interconnect with conductive insulators.
Sommer coats the Carbokab cable conductors with a conductive plastic. Said it reduced skin effects. The Albedo and Zilk cables have the conductive plastic outside of the foamed PE insulation to provide an additional layer of shielding.
No info is provided to how the conductive insulation used in the Kimber Carbon headphone cable is utilized.
The technical explanation is it drains the capacitive charge built up in the cable. So it maybe in contact with the conductors.
Maybe Kimber will soon release Carbon series balanced and single ended interconnects.