I'm afraid you're not going to achieve anything noticeable with 5% bleach.
To bleach furs and hairs, eg squirel I use a product that I sourced from a hair dresser. It's not available over the counter to the general public, just through trade suppliers. (Makes you wonder if the products women apply to their heads offer some explanation of their character traits!

)
Anyway, it's a two part product, liquid and blue powder that's mixed and applied with something like and old toothbrush and worked into the material, then left for a while to do its stuff. How long, trial and error - too long and you'll 'burn' the hair or fur.
Obviously, before you start the pelt or tail needs to be absolutely clean and degreased.