Is Bleach-White bad?

I use bleach white to clean my tires every time i wash my car, is that a bad thing, cause i've notcied that my tires are starting to crack up arround the side wall like they're drying out...is that because of the bleach-white or maybe the shiny stuff??? thanks

What tire product do you use for shine?

usually i use, i think it's meguiers, purple gel stuff...but lately i've been using eagle one, and i've used Armorall a couple times