or Arena Products' "Super White Shampoo" The guy who ownes the company shows Arabs. I actually use it on my brindle & white boxers ans as its a colour enhanser really brings out the colour and no next day dandruff we get sometimes. Great stuff and great guy too.
We use Fly Away Ultra White shampoo on Molly's feathers and they come up gleaming - have also used it on the front of my Bernese with mixed results (but she is usually really dirty!!!)