As above really, The colour magic will work and mask \ fill in the swirls but it isnt going to give a great finish and will only give a very temp fix.
As Johnny said if it has been through the swirl a matics every sunday morning or using a nice gritty sponge thats been around years, you are just going to waste your time trying to mask all the defects.
But doing somthing is better then nothing at all, and TBH most buyers have not got a clue about paintwork as long as it is clean and is slightly shinny that will do for them.
If you do decide to go down the coloured polish, make sure you wear gloves as it makes a right mess of your hands.
Like said though you are prob better off going down the Megs three stage and clay bar route.
The only real fix is to get it properly detailed.