Most of the kits are good nowadays. Both the Meguiars and Cerakote kits work well.
This is the one I’d recommend.
If you want to really get after it, wet sand with 800, 1000, 2000 and 3000 then compound and polish. Finish with a clear coat of your choosing.
All in all you’re removing the oxidation and adding a UV coating to them no matter what process you use. There are different ways to manage that but elbow grease will always be a part of it unless you have a polisher.
If someone says it didn’t work, they didn’t remove enough of the oxidation or used a crappy protective coating.