Fill a small bucket or bowl with hot water. Put a denture cleaning tablet in the water and allow it to dissolve.
Wet a sponge or washcloth in your homemade cleaning solution. Vigorously scrub the affected window, paying special attention to any areas that feature film. If the film is particularly stubborn, tackle it with a soft-bristled scrub brush.
Soak a sponge or washcloth in hot water. Wipe your etching film-free window in a circular fashion until all of your homemade cleaner has been removed.