NOTE: ALTHOUGH SAFE KLEAN APPEARED PROMISING, I WAS DISAPPOINTED IN ITS RESULTS. HOWEVER, WE CONTRIBUTORS DID COME TO SOME OTHER GOOD CONCLUSIONS, AS WITH HELP FROM SOME TOP EXPERTS IN THE FIELD. - DOUG
As someone who is quite sensitive (perhaps even allergic) to organic solvents and who is not satisfied with water-soluble oils (particularly the whites, not ground in linseed oil), I have a keen interest in safe, effective substitutes for turpentine.
Gamblin has a good chart comparing the advantages and disadvantages of oil painting solvents...
http://www.gamblincolors.com/materials/solchart.html
However, as you may see from that, none of those solvents -- including Gamsol, Turpenoid Natural