Pressure Cleaning / Steam Cleaning / Degreasing EFI Engines?????

Is it OK to use either or all of the following to clean a '89 EFI T3 transporter engine?
pressure / steam / degreaser spray & water jet

I have never needed to clean any thing other than carby engines so I'm a little unsure as to whether I will do any damage to any of the EFI components.

Is there any thing to stay clear of?

Can I start the engine while it is still wet from the cleaning process or should I wait until it dries?

look forward to your advice.

Cheers
Brendan