It is possible to take out swirls by hand but what can sometimes happen is that the abrasives in the product is not broken down well enough which can cause marring/hazing. So I would highly recommend using a PC with a polishing pad and work the 3M SMR right before it dusts up. However, please keep in mind because of the oils/fillers in 3M SMR, I would recommend using a mixture of 50/50 water/alcohol to wipe off any oils/fillers as you go. This will help you determine if the swirls are actually being removed instead of being covered up.