What you need: Water, vinegar, spray bottle, and a funnel or extremely steady hand :)
Add one part vinegar. Vinegar is a mild acid, and is what will remove the grime. Either fill the container half full or use the same measuring cup for both ingredients.
Add in the same amount of water as vinegar.
Shake the bottle to mix it all up.
Spray the glass cleaner on and let it soak for 10-20 seconds. Then scrub, and wipe dry.
Look how clean and shiny it is! This cleaner is slightly streaky, but I prefer it over the more chemically store sprays.
For more homemade cleaners and other stuffses visit my site TheHomemadeExperiment.com