Today’s thrifty tip is use plain water instead of windshield wiper fluid. I use plain water and haven’t noticed any difference. I have seen many recipes where you can make your own using either vinegar, dish liquid soap, or rubbing alcohol. The problem with using any of those ingredients is it could harm your hoses and/or seals over time. I do buy windshield wiper fluid, but if I run out or can’t find a good sale, then I do use just water. I also don’t live in a climate where I experience freezing weather. I don’t have to worry about fluid or water freezing in my reservoir. I find the water gets the grime off.