I've always gotten great results with Zaino products.
I don't have problems with swirls on my car...but I have used Zaino Z-5 Pro on friends's cars to remove swirls - by hand. As others have said you need to be patient and do one section at a time - over time.
Z-5 PRO Show Car Polish for Swirl Marks and Fine Scratches: Zaino Store
It's best to follow the Zaino instructions, and use their ZFX Flash Cure Additive. A little Z-5 goes a long way!