How do you do it? (Or do you bother?)

Mask off any electrical bits with cling film.

Get some Autoglym machine and engine cleaner and spray over the whole surface, agitate this using a decorators radiator brush. Hose off. Clean up any loose water with paper towel, and if you really want spray Autoglym Vinyl and rubber care over the whole engine to make it shiny.

I've found the easiest way for me has to use a white spirited laden old toothbrush to do the chassis bits and complicated areas to reach. And tyre dressing seems to work on all the rubber bits like the airbox/battery box/engine top + pipework. Then metal polish for more metallic bits.

For general degunking I've found nothing better than my old toothbrush and white spirit. (applied fairly carefully though)

a very good guide here

www.polishedbliss.co.uk

Oh yeah, forgot about that website - Its still in my favourites.

This was how much engine bay came out, and it was well mucky beforehand. And this was only a 60% effort put in job.

Steam cleaner.

Compressed air line.

Not your average equipment I give you though.