Once you've removed the swirling with a machine polisher, they only come back when washing if the incorrect methods are used.
Not saying there is a right or wrong way to wash a car...everyone has their own approach. But if its putting swirls back in, then you need to review your process.
I use a decent snowfoam to break down and remove 80% of the crap, a soft bristled detailing brush to get in all the nooks and crannies, pressure wash off then again of needs be. Wash with a soft microfibre or lams wool mit and use two buckets and you should have no issues with swirling for a long time.
If you have a decent wax on too, a weekly wash routine (if possible) then the snowfoam should do most of the work and speed up the process.
If you're washing the dirt and grime off without a pre wash treatment other than getting it wet with the pressure washer, or using sponges etc then washing the dirt into the paint is when the swirling starts to re appear.
If you are relying on using a polish to "fill" the small scratches making them look less visible, then yes they too will start to come back. You will need to cut the top layer back with a decent machine polish and cutting compound. Hand just won't cut it unfortunately..... no pun intended
hehe
Hope this helps