Claymore has a lot of white. In the warmer part of the year I have to bathe him quite a bit. He likes his green stains. :roll: I usually try to bathe no more often then every four weeks, sometimes I can go longer, but it doesn't always work that way. I do use a spot cleaner when I can get away with it. I usually use a whitener shampoo on him, hand graze him while he dries, and once he is dry I coat him down really heavy, head-to-toe, with show sheen to try to repel dirt and staining as much as possible in between baths, that does help a lot.
I have a black and white mare I have to bathe just her back legs, at least once (and preferably twice) a week. But that is because she pees on herself - I would rather face skin stripped of oils than fly attraction and skin infection risks of pee-soaked legs on a horse.