[DaveKG]

A product like Ultra Deep Shine achieves the vast majority of its defect correction by filling swilrs to mak them. Autoglym Super Resin Polish contains very mild abrasives, but its the fillers in the product that do most of the work, however by hand this is an effective way of dealing with swirls. Also, on cars where the paint is very thin and machine polishing with abrasives is just not possible, then filling swirls with these products is a good option.

If you are keen to remove swirls rather than mask them, my first port of call would be Meguiars ScratchX.