not running after engine degrease

[Niall]

Never wash a engine bay without thoroughly sealing up anything electrical

Hmm, I don't really agree with that, I've cleaned engine bays loads of times now without covering anything. Just don't blast water at plugs and take it for a quick run to dry off after.

If somethings gonna fail from water ingress, I'd much rather it was at home while cleaning than the next time I hit a puddle!

You're lucky then. Ive seen plenty of people cause some rather serious issues by filling old brittle plugs with water or destroying ECUs etc