I've used bare wire ends with 47 Labs OTA 26 gauge solid core copper (used a speaker cable) for almost 20 years now without any problems.
In the early stages I would strip/replentish the ends every year, or so, but as I noticed no oxidation when doing so I abandoned the procedure.
This was on the amp end as I generally soldered the cables directly to my various single driver speakers.
The few times I tried soldered or screw type connectors the SQ went South.
However this would most likely be dependent on the cable/connectors used as well as the system itself.
My rational is that reducing large metal masses in the signal path is a good thing and with this thought in mind my 47 Labs RCA connectors contain zero metal aside from the copper cable used in the interconnects.
DeKay