Hello Customer (name blocked for privacy),
The absolute best product to remove any sticky substance from any surface is regular gasoline or white gas or paint thinner. Just lightly soak a rag with gas and pull off as much gum as you can. Then rub the gum residue off with the rag. You may also use "Goof-Off" . I personally use gasoline to remove glue, gum, and any other sticky gunk that wont clean up with water. Due to its solvent properties, it will leave a film on the surface of the glass that can be removed with windex or other glass cleaners. I know it sounds weird, but trust me on this one. Im a woodworker, electrician and all around handyman. I have used this method time and time again. It is completely safe as long as the gas doesnt drip into electronics. Please be sure to take the rag outside immediately after cleaning the gum up. Rinse the rag with water to dilute the gas and keep out the possibility of ignition. And keep all flames and heat sources away from the gasoline as well as providing proper ventilation when using it.
Good luck,
Chris
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