Wax on a tire, no matter where is not a good idea. Same thing as not using any tire shine products on the tires.
+1. If you occasionally drag your pegs like me, JPR advice is absolute. It is amazing how far up the sidewall you can be and still control the bike. Tire shine acts like a lubricant and at that moment during a steep turn you don't want those molecules to do their thing. I only did this once and survived just to tell you about it.