For this kind of rust removal I tend to use steel wool and a sticky oil like Hoppe's gun oil. Chainsaw bar oil would probably work too... anything that doesn't run down the column too fast and also lubricates should be fine. An alternative I've used for heavy corrosion that pulls steel wool apart (but doesn't justify power tools with wire brushes, etc.) is green Scotch Brite pads and oil and then finish it up with steel wool.