1.) It is not just a field full of mud. It is a field full of mud and every child for a 30 mile radius.
2.) Have a high adult/kid ratio
3.) Bring two towels...one for mud and one for after the hosing.
4.) Have a meeting place, you will not be able to distinguish your child from the others once they are all the same color.
5.) If you don't plan on getting muddy, plan on getting muddy.
When we first moved here, I worked at a little consignment shop for kids. One day, a mom came in buying clothes for her kids for right then, because they were covered in streaky, slightly dried mud. She told me about Mud Day. The parks department fills a field full of mud, the kids play, then the fire department hoses them off. I have wanted to go ever since...that was 5 years ago. Due to other plans, babies being born and simply forgetting, this was the first year we could go.
I can't say Lucy loved it but I think she had some fun (I should probably take a Xanax before I go because I had mini anxiety attacks when I'd lose sight of her in the crowd) and I think we'll try it again next year with some experience under our belts.