I second using a wash made from water and water-soluable acrylics, over any commerically-made washes made from other media, like enamels or oils and mineral spirits, or any kind of lacquers.  And remember that "acrylic" does not mean "water-soluable". Many brands of acrylics are water-based, eg, Andrea, Vallejo, but there are others that aren't.  We've got a number of discussions here in the forum to explain the chemistry, which are good for reference.

I like to use water-based craft store brands and plain ol' water to make washes, generally.

Best regards,

Brad