In another topic I mentioned that if you are cleaning parts that are 100% metal, then the best stuff to use is some kind of petrochemical organic solvent, such as acetone, mineral spirits, isopropyl alcohol, or even gasoline.
...However...
You should never use any of that stuff on plastic or composite parts, at all. Some of it will dissolve plastics.
For plastic or composite parts, just use hot tap water and one of the "soap" cleaners.

When using the flammable stuff: do it outside, don't get it on your skin, it may eat through latex/polyethylene gloves, it's usually flammable, ect.
The health risks are minuscule if you only mess with it a few times a year. Ask your own doctor about that matter.