How is the engine washed?

Hello friends ... I want to wash the engine of my 2009 model 1.6 hdi, but I am afraid that electronic components will be damaged.

Have a look at my teacher here

Just as I have seen in the forum before, you can reach more detailed results. My personal idea and self-application is to use a degreasing spray first, then use a greasy and meticulous surface with a damp cloth, and then I use a plastic polisher with metal parts. I polish without overdoing it.