The reps for that company itself (when I asked them online) do NOT recommend using it for
EPDM/rubber parts at all.
But many seem to swear by it for hard
textured plastic (but NOT smooth plastic, for some reason?), like our fog lamp surrounds/inserts, and rear bumper valance trim, etc.
I think that I will just replace these moldings/surrounds, and SOAK them in Aerospace 303 before installation.