After discussion with some friends, we decided to run our own messy games day, which we christened 'Messtival'. This means we could take part in the games, and they could be as over the top as we liked. The event has now been running for a few years and has been growing in popularity each time.
I do not make any claim that any of these games are completely original, and thank those people whose ideas I have adapted over the years.
This Instructable will take you through how to run a similar event- there are many ways to change it to suit your needs, but I hope it gets you started. It would be great to hear your ideas in the comments.
I won't reproduce the mess recipes here; please see my other Instructables where I have fully described them.
Gunge Recipe http://www.instructables.com/id/Gunge/
Slime Recipe http://www.instructables.com/id/Slime-1/
You will find examples of other clean games and obstacle courses at my website http://www.superpants.net/games.html These may eventually form a new Instructable. Also on the site you will find loads more info on making mess.