How to... safely clean an engine bay

[Debo]

Cling film maybe?

Cling film or similar (I used freezer bags in the opening post in this thread) will be fine, though tinfoil is fine and accepted worldwide. You are only covering electrical componants and connections, the reason for doing this is so water isn't forced into any important wiring under pressure. If you look at my pictures, you can see the areas I am talking about

If a battery is present in the engine bay, like on a Punto, the positive terminal is likely to be covered by a rubber sleeve, so you would only need to cover the negative, whatever the circumstances, you wouldn't need or want to cover the whole battery, because you'd want to clean it!