Mineral spirits works good, but I find it really dries out my hands, bringing on those painful finger cracks, especially in the winter. WD-40 works really well also, and is a lot easier on the hands. I buy it by the gallon and put in spray bottles. I spray everything that moves with it, and most of the stuff that doesn't. Equipment that sits out all the time really benefits from it.
I have a box of those cheap latex gloves that I use every-time I grease or clean the the grease on my tractor. My grease gun always makes a mess and this red grease sticks to everything. It never fails somehow the grease gun extension hose gets me and everything else every-time. When I'm done I just peel the gloves off and throw them away.
WD 40 is great for spraying on and leaving it on for protection but is a poor cleaner compared to this. it doesn't dissolve the grease as well and it doesn't leave a clean Wax-able

finish behind and I can't take the smell after awhile.
I buy a "box of rags" that's what its called at the hardware store. Its cotton tee shirts. I pour a good amount of this odorless stuff onto the rag and just "wipe" the grease away. The grease dissolves and sticks to the tee shirt and doesn't smear it all around.
This brand paint thinner is very mild and seems more like white kerosine than paint thinner. I say that because its more oily than lacquer thinner I have no experience with other brands.
I use WD 40 all the time for many uses, when I first got my Kubota i sprayed it on all the bolts, nuts, washers and linkage underneath the tractor to keep the hardware with that yellow "factory finish" pretty sick hah
I would spray it all over my backhoe hardware, pistons etc. before covering it with a tarp for the winter. Sadly I did not do it this year. I slacked off a little in the last year and I have to do a little catching up.
My tractor is more of a toy for me rather than using it for a living or on a farm. For those of you that do, I can see where you would think Im crazy.
I do use it though 587 hours and counting, 500 of them mine. (Of course a lot of that time is idling out in the field with the AC on watching movies on the DVD ).

kidding