^^^ I dunno wallaby, she looks very purple to me in your signature!!
I don't know much about getting out stains because I've never owned a white horse, or grey.... (but I may have to learn soon because we may be getting a grey mare to race
) anywho, a woman who has a white horse at the track has no problem using dish soap. Especially there is one that has a "power of oxyclean" in it.