MEK is awesome for diff cleaning. Methyl Ethyl Ketone and a Tea Strainer. Slap your parts in the strainer....put some MEK in a Mason Jar and dunk away. @ 30 seconds and all the silicone/grease melts away ;-) Just remove any O-Rings and what not first since it will melt those too.
A buddy on another forum told me about MEK, and I've been using it ever since. You can find it in most hardware stores in the pain section (it's a thinner).