The water : bleach ratio is that like mentioned, not sufficiently damaging to your equipment.
Like I said, it is used for sterilization, not every time you clean your brushes.
Some use 50/50. I use about 1/3 bleach and then use mild soap so that it doesn't irritate my horse.
I've never had any trouble with it. And the smell is barely noticeable in the soaking process, and completely gone afterwards. I think it is a great way to thoroughly clean your grooming supplies.
distances are like men. never grab the first one you see; it's never the best one, more will come along.