I’m proud to say, after some experimentation with different formulas, that I’ve developed a no-streak household non-toxic glass cleaner. The one I had been using prior, which is all over the internet, was a vinegar/water combination with a little bit of cornstarch thrown in. This worked just fine for me, but apparently most people are just too lazy to use the arm muscle to rub all of it in so that it doesn’t streak. So I set myself the task of developing a non-streaking glass cleaner, with the most minimal input of materials possible. One formula I tried was with rubbing alcohol, and this one worked exceedingly well, but I had 2 problems with it: 1) it smells like rubbing alcohol!, and 2) the ratio of isopropyl alcohol to water just seemed too high to me to make it cost effective on an institutional level in comparison to my original formula.
The second formula I tried, and this one was my own concoction, was with hydrogen peroxide and water, with a pinch of Dr. Bronners liquid castile soap thrown in. This worked well, and it smelled pleasant as well, so I fiddled around with it to see how little hydrogen peroxide I could get away with putting in there and have it still be effective.
The resulting formula is as follows:
2 cups hydrogen peroxide (normal over-the-counter 3% stuff)
1-2 drops of Dr Bronner’s liquid castile soap
1 gallon of water
Modify according to your dispensing system, of course. If you are putting directly into a spray bottle, that would be an 8-to-1 ratio.
It sprays a lot of liquid onto the mirror or glass at first appearance, but even if you don’t rub it all in, it all evaporates without any streaking in the test trials that I have done so far.
The formula may require some tweaking; I’m going to perform some more tests on it before switching over all my 55+ glass cleaning spray bottles.
Update: It works really well so far, so I’m sticking to the formula above.