I use the 3m products and yes its a paste that you can buff out by hand using a micro cloth or if you really want to do it right use a power buffer with a wool cover.
so far it has never failed to take off any black streaks for me. There are two types of 3M products - one is to be used if you have heavy oxidation called Restore and Wax - if light
oxidation use the one called Cleaner & Wax. - Once you have used the Restore & wax once - you put a normal paste wax on after it. If you keep the trailer washed and just just a regular wax on the trailer a couple of times a year you should not need to do the restore and wax again. I keep a Clean and Wax bottle on hand for using through out the year to get the bad black streakes and bug stains off that dont come off while washing the trailer.