For my greys what I do is I will wash them with the vetrolin White N Brite shampoo and let it sit for a minute or two. Then I'll rinse and do the gallop shampoo for greys. Again let that sit.... (they're both purple shampoos) rinse that out... and what I try to do is clip them as often as I can because that the only way to 100% get off stains. And green spot remover is great!! Basically you will spend a lot of time grooming, (curry and a hard brush will be your best friend) and you'll also spend a lot of time batheing, clipping etc. If you want them to stay show ready white most of the time. Hope this helps good luck!!