If there was ever a snake oil product, that is it. You are not going to hear a difference in ground cables. It is either grounded or it is not. The reason the ground cable provided with some turntables is super thin gauge is because it prevents a solid or rigid connection, as that would be a path for vibration to travel on. The thin gauge is sort of absorbing vibration like a spring rather than transferring it. You can just use any thin 22 or 24 gauge wire from say an auto parts store or hardware store. If you fancy expensive silver, then use that...it ain't going to make one bit of difference in the sound. No ground? Well then you have an issue(s), such as hum, buzz, erroneous noise etc...
Grounding cable gauge size
For those of you using external grounding source devices, units such as Entreq, Nordost, Synergistic, etc. What size wire gauge seems to work the best?
ozzy