I used to do a bit of pay and plays and the ****ye got everywhere, I reckon you need a petrol pressure washer and a couple of 25 litre barrels of clean water to get the worst off before leaving the site as once its dry!
You will never ever get all the mud out of the chassis even with a pressure washer, I even drilled all the chassis drain holes out to 3/4 inch to help get the crap out.
Killed starter motors as filled up with slurry, in the end I had two rebuilt spares ready to go on, the same slurry wore the alternator brushes out pdq so quick I carried a spare brush box, also used to get in the front support bearing on the pas pump and fook that up and as for wheel bearing bugger me the car ate them no matter what make, the water/mud did for them.
Dont forget to fit the timing cover and clutch housing wading plugs if not the same old mud will kill your cam belt tensioner and destroy your clutch, I know ive done both!
But most expensive potential problem on 200/300tdi is the injector pump, not a lot of people know this but the boost capsule on top of the pump one side is sealed the other is open to atmosphere via a little rubber nipple on the back of the boost capsule, water can and does get in here and can seize up the fuel pin at the bottom of the tapered fuel pin, this also happened to me and took some working out why it was down on power!
The very next day you need to grease all points to push any water/mud out and check all trans oil levels in case you have got water in the oil.
Wellies are essential
Great fun but be prepared and even if your are prepared it will still cost you money either that day or some time later in repairs.
Arent I just a little ray of sunshine?