I used these to add volume to the conductors in a home-made quad type speaker cable. The conductors were Audiophonics 4 sqmm silverplated hookup wire with PTFE insulation. The purpose was to reduce the potential for cross-talk between conductors.
This cotton sheath was perfect for the job. It was easy to insert the conductors and then stretch the sheath to a tight fit. The knots in the weave also made it easy to twitst the conductors together.
The natural cotton also adds a beautiful aesthetic to the cables, so I would recommend using this sheath as often as you can in your builds.