Yup, been there, done that one.....
Sorry, but your best bet is kitchjen products and elbow grease!
Tried many variations on the vapour cabinet technique, and few have proved particularly successful, and almost ALL have been peculiarly hazardouse.
For greasy things, cheap, big box BIOLOGICAL washing powder, litterally 'eats' oil, but you need to scrub, rinse, scrub, rince, and keep scrubbing and rinsing to work through layers.
For really stubborn carbonised deposits, like engine bits where the oil has charred to a laquer, oven cleaner.
Its an oxidising agent, again, apply, leave te oxidise, scrub, rince and repeat.
Between the two, theres not a lot you cant shift.
Nitromours type paint stripper works reasonably well, too on things that have unwanted finishes like, well, paint.
But you do need to be careful where and what you are tackling; oven cleaner particularly, as an oxidising agent oxidises anything it touches; spray it onto an oly bicycle chain, it will take the grease off a treat, but leave it over night and it will be red rusty by morning!
Aluminium, the white furr is already an oxide layer, and the soda in oven cleaner wont get that off, it will make it worse! Some of the Nitromours strippers will work better here.
But, beware, many ali parts have a surface finish called alochrome on them.
Its NOT like anodising which is a carefully applied oxide later, a bit like galvanise, that forms a skin over the top to prevent further oxidation, and allows some self healing if the surface is scratched, but a chemical 'hardening' process that forms an aluminum 'salt' in the upper layer of the metal, thats hard and oxide resistant.
Use a harsh agent on it, and you can 'eat' that hardened layer away, making the part weaker, and expose it to oxidisation.
If you want to persist with a 'boil' technique, practically, best results I've had have been with simple washing powder or washing up liquid, and a very small amount of water, the parts being cleaned suspended above the layer, so that they are sitting in the steam...
Principle is, that the hot vapour heats the parts, melting the grease on them, water condensing on the part can then 'dissolve' the grease into the water as it runs back into the boil..... but I've found it only ever really shifts surface slime, and you are back to bottle & toothbrushes, scrapers and cocktail sticks to gouge out stubborn 'grime' and patient repeating of whatever processes you use between.
Best use of the primus in the workshop?
Well apart from boiling the kettle to stop the missus moaning about oily finger-prints in the Kitchen......
Old baking tray, with 2lb of LM grease in it, sat on a thick bit of old metal (old SIII towing plate I think!) to spread the heat and stop the grease boiling, to dip Dirt-Bike final drive chains in, and get the grease into the links.........
