It is not necessary to fog a diesel as one does with an outboard. The natural lubricating properties of diesel fuel are fine and the engine oil should coat all the internal engine surfaces to guard against corrosion. There are a few extra precautions to take however;
1) make sure that the fuel tank is full to ensure that condensation doesn't form
2) lay the engine up with fresh fuel filters and fresh oil and oil filter after running the engine to ensure that all is good
3) run potable anti freeze through the raw water system to protect it from freezing
4) remove the raw water impeller and coat with Vaseline and place this impeller on a piece of cardboard to avoid staining the area where you keep it. This will help it to not crack so it is still useful.
5) drain the exhaust system and raw water strainer and cover the exhaust outlet, close the intake valve etc.