Back in college (yes, email was just being discovered and I typed my term papers on the first Macintosh - a "portable computer"), even back then we were actually trying to be environmentally conscious and often used Simple Green to clean up our oil painting messes as an alternative to turpentine and other noxious stuff. Amazingly enough, even though personal computers have made leaps and bounds, the environmentally conscious oil painting artist is still left with... Simple Green.
- wiping all excess oil paint onto our palette and then onto a paint rag
- rinsing brush in a turpentine based brush cleaner (using a wire coil at the bottom of a jelly jar to help dislodge as much oil paint as possible and then re-seal with the screw on top for use again later)
- spraying brushes down with Simple Green and further working bristles in a utility sink
- finishing cleaning with a mild soap and water