Dish soap will take wax off. I don't know if it's necessary to remove wax.
I'd just use a mild soap as you'd do any other time you wash the wheels. Then quick rub with Alcohol as indicated above.
I have zero personal experience with Plastidip, but I have a friend who had absolute hell getting it off a car he was installing a "wrap" on. After seeing that I have avoided the stuff. Many other people don't have these issues...so maybe it had to do with prep, or with the thickness the plastidip was applied. (thicker is better I've been told). Best of luck with it.