My old boat was a '78 Cal. Every product we used to work on oxidation did work for a short time, but only a short time. A month after dipping the old girl and she began to show her age again. We found that on the old boat (your boat does not seem that old) we had to go to wet sanding.
We did it by hand: not with a orbital sander (Don't think I would recommend using an orbital sander). The results were very impressive. Also found with a heavy oxidation that it was actually less work to wet sand than it was to use a mild rubbing compund, the sanding actually required less elbow greese, the results were superior and longer lasting.
The technique was very simple. Wet, sand, remove residue, polish (3M Finesse It), and wax.
Do your homework and research, I was working on a boat that was 25 years old at the time not six years old. Don't think you should be seeing such poor result with a boat of your age.
Are you applying good quality marine wax to protect your boat?
Thank goodness our new boat is awlgripped. Nothing could be easier.