I don't know why you want the solvent to not be water, anything else is likely to be more polluting.
For aqueous solutions a fairly striking and practical one is urea. It has the advantage of being very water soluble - more than 1g/g and you get a quite noticeable cooling effect on making a concentrated solution. It is cheap. And afterwards you can spread it on your garden or pot plants as fertiliser. Not too concentrated near any plant and I believe an even 5-30 g/m2
An outline of the interactions involved is here http://www.chemtopics.com/aplab/urea.pdf