If for any reason you dislike mud edits (and my interest in it isn’t even a fetish, though I know it is for some), including finding mine to not look realistic enough (despite my best efforts to make them look realistic based on pics from the show), ignore and go on to something else.
I guess I need some story to it as well, don’t I? How about… Rushing to her performance, Rarity tripped and fell in the mud. Though covered in mud from head to toe (or rather shoe) this didn’t stop her performance, and the audience loves her. Looks like she doesn’t mind getting dirty as much as she used to. But, she still took a long bubble bath and shower when she got home.