After you have it all nice and clean again, perhaps you could throw a large tarp over the whole thing if storing it out in the weather again. My poor trailer is about to experience being stored outdoors for the first time. I only have a one car garage and it has been in there since I bought it, but now I have a new car, and I'm afraid that is now going to have to go in the garage. I've rented an undercover park at a storage place, so hopefully the fact that it has a carport type cover over it will protect it a bit.
It's all fun and games until someone gets hurt - then it's bloody hilarious!