i was wondering what your methods of keeping your cameras clean underground are when using them in muddy caves.

alastair

Mine are mostly based on cure rather than prevention! Insurance, and plenty of bar towels... 

who are you currently insured with, i am with photoguard but am not 100% sure if they will cover caving

Clingfilm around flashguns works well, too.

Wear gloves which keep your hands relatively clean. Then take off the gloves after opening your bag, but before handling the camera. Clean your hands on a bar towel. Then you can handle the camera keeping it relatively clean. I put the camera in a clean plastic bag inside whatever protection I used for carrying it, so it is easy to get out without getting mud on it, and you have somewhere clean to put it down.

After the trip I wipe off all the mud and dust using baby wet wipes.