Here's the verse:-
"Vinegar is a 5% water solution of a small organic acid, acetic acid. Acetic acid is a polar molecule. Water is also a polar molecule. The acetic acid dissolves completely in the water because both are polar.
Grease is a mixture of non-polar molecules. It won't mix with either water or acetic acid, so no, vinegar won't by itself remove grease, any more than water by itself could.
That's why people use soaps and detergents. Soaps are made from long chain fatty acids that are mostly non-polar because the long chain, called the tail, is non-polar, but they have a polar end, called the head, where the acid group is connected. The grease will dissolve in the non-polar chain and the polar end is water soluble so it dissolves in the water.
This is made possible because the soap molecules, in the water, group together as a sphere with the water soluble “heads" on the outside of the sphere and the insoluble non-polar chains (“tails") on the inside of the sphere. These spheres are called micelles and they permit the molecules of the grease to move into the interior of the micelle and the micelle stay dissolved in the water because the water soluble parts are on the outside of the sphere.
So, to get the grease off, you need either a non-polar solvent, or you need soap and water. Vinegar could replace the water in a pinch, but would leave the stuff washed with it smelling like salad, and it still wouldn't work without the soap."