Seriously?
The current in a speaker cable will rapidly switch direction. So therefore the orientation of the cable is irrelevant.
There. Better?
Single ended signals are better defined by alternating current biased by DC because the voltages do not swing around a neutral. There is no zero crossing point with a true audio signal. I know, I know... hard to wrap you head around, but it is true. Balanced? A completely different reality. There is + (hot) and - (cold) that does swing around ground (center).
Hard to accept that in 'some cases' cables are directional, but there is just too much anecdotal evidence to rally a differing, "snake oil" position that holds water.
Directionality does defy conventional wisdom, but it really is a thing.. again, in some applications.
I can't think of a better example than the stock Mac mini power cable. If you are using a Mac mini, listen to a few tracks and then reverse the polarity of the power cable at the mini. The differences are not subtle. Part of this is due to the mini power supply wanting to see a particular hot/neutral orientation. The other part is the crappy copper used in the power cable. Chinese copper is some of the dirtiest copper available with huge carbon and other impurities. Couple this with the crystalline grain structure and there you have it. How do I know this? It is truly classified information from... you know... them. There is a reason why important connectivity systems and subsystems related to government applications are not sourced from China.