It also may depend on how hard your clear is, we have 6 vehicles and only my sisters Explorer and a silver Lincoln Towncar we have, have rock hard clears that I could only remove 50% of swirls with OC and yellow cutting pad (whats weird is my Mountaineer, same as Explorer, was fairly easy to correct as was our Lexus LX470).

That, or you may just need to work it correctly, as if OC and cutting pad don't remove/correct stuff, time for a rotary.