[Peter J. Fasi]

I have been using Mineral / Baby oil for some time now, because it is fairly inexpensive, because the smell doesn't smell so oily and because it works. I simply fill half my cleaning jar with it and swirl the brush against the wire mesh in order to clean off the paint. The paint particles simply drop to the bottom and the oil stays pretty clear for a very long time (depending on how often you paint). In between session I pour the 'used' oil through a coffee filter into a similar sized jar, transfer the screen and lid to the other jar and I'm ready to go.
I don't have to be concerned about toxicity. I conditioning the brushes as I use them, and it wipes off cleanly without any oily residue.

For me, this is amuch better alternative than the water-miscable oils.
I tried using them and did not like the feel (too sticky). I also prefer to have a much larger choice of traditional oils, in larger sizes.

Best of all, my wife no longer complains about the awful smell (unless I use certain Winton oils, which for some reason are particularly pungent).