Hey Hoodiemess, just wish to ask what fabric exactly is this one made from? To be really honest, the answer to that question will also determine just how messy and in what you can get it without totally trashing it permanently.
Wish you luck with it mate.
Also, if you're somewhere that's experiencing low rainfall at the moment, you could always try making a nice muddy patch in your own back yard if you have one. Just add water to the dirt ground there, and of course, if you're somewhere currently experiencing drought, please use grey or recycled water from your shower or something, just to do your bit to conserve water in your region.
Love you, too
