I have standard cerakoted guns and I have guns that have been parkerized and then cerakoted. The ones that are parkerized first seem to hold up better as the parkerizing acts as a primer so the paint bonds better.
You will have to abrasive blast off the cerakote probably with either aluminum oxide or garnet media but it will probably leave a rough surface. I'm not sure if glass beads will remove cerakote but they might.
