Barrettine Genuine Turps is a traditional thinner used for varnishes, artist oils and other paints.
Genuine Turpentine dissolves polish and beeswax components etc, and is often used in the manufacturing of beeswax polish.
It is used to clean brushes after painting with oils.
Equally, White Spirit can also be used to thin traditional paints and Cellulose Thinners are great for cleaning brushes!