I don't know about how pleasant is it, but we had a horse that loved going to the car wash. I never used the soap on him, nor did I use full pressure up close, but he would stretch out and roll his back around like "get me here, mommy, it itches right here!" He was white, and it was the only way to get him clean, and keep him clean, before a parade. We'd stop at the car wash on the way, and let him air dry in the trailer.
Plain Old Dee, horses Dancer and Rain I believe in dragons, unicorns, good men and other mythical creatures!