This is just a general FYI. New Zealand is trying a new mud festival called Mudtopia, in Rotorua this December (thats early summer for you northern folk)
Rotorua is internationally known as a place for geothermal activity, geysers etc.
Sploshing meets the public, a bit of harmless fun .. probably all of the above. So there you go, if heading south has been on your bucket list. Now you have another reason