Paint cleaners are only meant to remove fresh stains, watermarks, and on some occassion very, very light swirling. Most contain some fillers to help hide swirls. They are perfect for brand new cars or keeping up a recently polished car. Good to use before each time you wax. AIO is probably the best and it has some protection in it, use klasse sg after. I've also heard that P21s is some very good stuff too, no protection in it. I've never used pinn. pcl, but I've heard its good too, no protection Their is really no need to use them after polishing, with the exception of AIO, alot of people use it after polishing. They will remove old wax or sealant, so if you use it prepare to reapply after. Their all good and do a good job, I would sayuse the klasse and get the klasse sg, that combo is bulletproof and last very long. I usually put to coats of sg on after polishing, giving one coat overnight, then I put some good wax, like pinn ls or nattys or sometimes a good sealant like wg or dp.