When I bath I typically just put the horse in cross-ties and use warm water to completely wet down the horse, then just use shampoo. For bathing the white horse (I leased a white horse when I was younger) the best shampoo that worked for me was "Miracle Coat Radiant White Brightening Horse Shampoo". It was hard to find sometimes but you can order it off the internet, which is what I did. And then I just used mane and tail conditioner! Then after you're all done scrubbing just use warm water and completely hose down the horse again (making sure to get ALL the soap. They get itchy :)"