Parkerizing is rough in part because it doesn’t do well on polished surfaces. One of the things properly applied microslick does is smooth everything down entirely. I expect that it would stick fairly well to the parkerized surfaces but I have zero personal experience with it.
I’d be interested in hearing your results!
As an alternative, you could soak the action in CLP for a few days then wipe it dry, and you’d probably running smooth for a long time.