If 100% completely dry, bleach is safe.
If still with water/wet/liquid ... bleach is very dangerous for your tank.
So, if you're hanging dry for a few days + are sure it's completely, fully dry ... no problem. Some seem to soak in anti-chlorine/bleach stuff [like Prime] to negate this issue. [I prefer letting them 100% dry, personally]
I have bleached mine from time to time [when I'm not using them that week, can let them dry and not worry] ... but generally just use the washer, nothing added. [extra rinse]