Yes. ColorX is a cleaner wax. Apply the swirl remover first, then ColorX, and top with another wax. I don't think a sealant would work well over ColorX.
NXT would probably be a good choice if you're looking for an OTC product.
Oh, if by "swirl remover" you mean Meg's #9 (Swirl Remover 2.0), don't bother. It won't remove any of your swirls. Even when used by PC it's near worthless IMO.