Oxidation removers don't "remove" a surface layer of something that will return the original shine underneath, they're an abrasive cutting/polishing/rubbing compound that polishes the surface to restore the shine and you need to learn how to use them correctly. Some compounds are more abrasive than others and you may want to test it on a less conspicuous spot first, like say a compartment door. For larger areas, a power buffer is the way to go and will give a better finish otherwise, old fashioned elbow grease will work but is slow and painful. Use a quality wax afterwards to help protect the gel coat and some 303 protectant on the decals and trim.
There's lots of oxidation removers on the market and lots of how to info. on the internet. Meguiars for example has a catalog of products for marine and RV use
here. They have a #M44 color restorer for light oxidation, M49 for moderate oxidation and M67 & M91 for severe oxidation and range from being lightly abrasive to heavily abrasive. Their website also has some good info. I doubt severe or maybe even moderate removers are a good idea on RVs.
Our front cap started to fade along the top last year after only 3 seasons. I used some Meguiars oxidation remover which helped somewhat but still not shiny like the rest of the exterior. I can't lean a ladder against the cap and reaching over from the roof is hard so can't apply enough elbow grease. I use a good synthetic marine wax every year but oxidation seems inevitable on RVs regardless. :(