A useful alternative to solvents is an orange oil type cleaner. Blackjack Tar and Asphalt remover works pretty well, and it is safe to get on hands and such. Once the grease and grime is removed, you can simply wash off the residual oil from the cleaner with regular soap and water. My main tools are plain old rags and q-tips. An old worn out hacksaw blade can be made into a very handy scraper for hardened surfaces like bearing races. Simply grind it to the desired shape.