I hope you did not wash everything!!
I have absolutely handed over muddy kids at the end of the day. There is a section in my handbook that states that "dress" clothing is not to be worn at daycare. And that, like Dream said, a dirty kid is usually a happy one.
I don't think I have had any parents yet that are cranky about it. And if they were? Tough tootsies.
I do feel badly on occasion, because inevitably, the days we have spaghett with red sauce are the days that ALL the children are wearing pristine white shirts. LoL. Whooooops.