What is VOSK?

When my mother was a young girl her mother made a salad dressing and they called it VOSK which stood for equal parts of Vinegar* Oil* Sugar* Ketchup. My son had some at my parents and liked it so I made up a bottle of my own (which has yet to be used). You see it's VERY sweet. It would taste much better with balsamic vinegar to give it some depth and with only half the sugar and even then it's still going to be sweet.