Get Artisan oils and just use water?
They are true oil paints, they just thin/clean with water vs turpentine/mineral spirits etc...
Although if I need to thin oils that are not water mixable, I find Weber Odorless Turpenoid great. Just note that "odorless" simply means "no smell" and not safer to breathe. You just can't smell but it is still as bad for you, if not worse since you can't gauge how much your inhaling so still take all the same precautions
Have not had a problem with it on Bandai stuff, but I also make sure not to let it pool in unpainted areas