I came across a tip that you can use Goop (the hand cleaner) to clean up a yellow tail. I tried it today on my boy, and it actually WORKED! I have tried whitening shampoos, etc. and never gotten the same results as this. Apply the paste to a dry tail, let stand 5 minutes, add a little water and work into a later then let stand another 10 minutes then rinse! It's made for hands, so I feel safe using it, and didn't apply it on the tailbone...just the hair that is below that. I will be doing this again in a week to get the tail just a bit more white, but the results were amazing so far. Oh, I also applied an entire bottle of leave on conditioner to the tail after rinsing out the goop to make sure not to have it dry out. Sorry I didn't have my camera with me