Have you ever washed your bathroom mirror, and then washed it again. And then STILL had it look smudgy and unclear? Turns out, you probably use fabric softener or dryer sheets in your laundry.
How does this correlate?
Fabric softeners and dryer sheets are far from vegan. They contain “fatty acids” and are indeed animal fats. These fats coat your fabrics and make them feel smooth and soft. So then if you are using your own “rags” you are trying to clean something and make it shiny by smearing it with the horrible cousin of lard. Those streaks are a little grosser now besides just looking bad, aren’t they? AND fabric sheets are also woven polyester = plastic.
I have found that the best way to clean windows and mirrors is with vinegar and paper towels. I have less hate for disposable paper products than plastics, but it still isn’t good to use something disposable when you can use something that has almost unlimited reusability, such as a rag.
So! How do you clean mirrors and windows and have them sparkling and clean each time? It turns out it doesn’t matter what type of cleaning product you use. I have heard of everything, dog shampoo, dishwashing detergent, straight vinegar, diluted vinegar, and the gamut of “window cleaners”, if you're wiping them with animal fat you will always have streaks. You have to choose to either avoid synthetic fat-filled fabric softeners and dryer sheets OR to purposely wash and dry your “rags” or towels without them. There may still be a bit of residual fatty acid covering on the inside of your dryer and your rags themselves if you have been using it for a while but that will eventually go away, especially if you wash on the hot cycle.
This way you can wash your windows and mirrors with just water and elbow grease as long as you are drying them with the right thing.