Hahahahaa - sorry, I didn't even read the posts. I read your title and immediately thought of Smokey and the Bandit 2? Or was it 3? With Dom Deluise and the elephant.
Hang your paint (using two straps around the front/back of the belly) to hang him/her from the barn rafters so his hooves don't touch the floor.
That will keep him from becoming a mud-pony.
Otherwise, I suggest you invest in warm water and sudsey soap. All the paints I have been around love to cover their white with as much mud as possible.
Maybe they want to be solid?