Many of the petroleum-based solvents discussed above are explosively combustable except for kerosene.

They're also carcinogens. They love to insert themselves into your DNA chains and make cancers.

Here's the old timer style:

After physically removing the most obvious caked-on solidified grease, with a knife, screwdriver or whatever is needed to get into the nooks and crannies, good old fashioned Lestoil has always worked well for me. Let it soak for a few hours in an empty jar, agitating it once in a while and then use a toothbrush on it.

A final rinse in hot water.

This is great for chains and freewheels.

Chuck a freewheel remover into an eggbeater drill, and spin the freewheel when it's submerged in the Lestoil.

Nothing explosive. I don't think Lestoil is as much of a carcinogen as the other stuff.

I don't own stock in Lestoil.