No, there is no miracle product, but look at these pictures of my engine:
1. Step one is to vucuum the whole compartment with the crevice nozzle of your vacuum cleaner. Get rid of as much dust, dirt, debris not forgetting the sound proofing under the bonnet.
2. Wipe down all the painted surfaces with a damp cloth soaked in proprietary cleaner (a good APC or any grease cutter). They are then polished and waxed to repel dirt.
3. If you really want to use an engine cleaner to clean the lower part of your engine, then care must be taken in spraying water. Personally I avoid this.
4. The alloy parts cannot be shone or polished in the conventional manner. They tend to go blotchy and get ugly marks on them. I use a toothbrush and a metal cleaner like Meguiars NXT Metal Polysh and gently brush the surface and then remove with a damp cloth. The cover at the front was chrome plated as it tends to get oil on it from the dip stick and the oil filler cap.
5. All plastic surfaces dressed with Aerospace 303. This is absolutely the best product I have ever used.
6. Thereafter it is a matter of a weekly wipe down every time the car is washed.
I hope that this is of some help.