Years ago I used a solution of concrete cleaner which is acidic to clean the alloy wheels of a Golf GTi. It got rid of all the ingrained brake dust and the wheels looked like new. All sounds a bit drastic now but it worked well. I don't think it would do much good to any painted parts if it were to splash or drip onto them though.
I've used Fairy Power Spray a few times.......Concrete Cleaner and Alloy Wheel Cleaner is most probably phosphoric acid, has many cleaning uses even in the catering world. Just depends on how much you dilute it. It is also a pretty good rust converter and the main constituent of Jenolite.
Agree with above as well. Buy some small artists paint brushes to get between the fins and those small places your fingers won't fit, spread the SDOC gel on, walk away, have a cup of tea, go back, rinse off, job done, if the dirt etc has been on a while it may need another application. It's also anti corrosive.
I would stay away from alloy wheel cleaner as I've seen it lift the paint on an engine. Stock 100 is great stuff if you use a bit of elbow grease and the rinse
