Are you still using oil-based paints? If so you could cut back on solvent use with cleaning your brushes with various vegetable oils.
Did you know you can also rub vegetable oil into a laser copy print and it will leave the printed image behind but make the paper almost transparent. This van be a a way of avoiding acetate.
This blog post seems pretty good about cleaning brushes.
https://justpaint.org/cleaning-brushes-without-solvents/