I contacted you recently about my son with Cerebral Palsy who has a pesky gray film on his teeth. We had been using Oral B tooth gel which we have since discontinued. I have been brushing his teeth exclusively with xylitol twice a day and giving him granular xylitol/xylitol mints about two or three additional times a day. We have an appointment this afternoon for his dentist to review his meds and take a look at the film.
Sorry but I have no idea what this film is from.
I really do not like the idea of the tooth gel - so it is good you have discontinued that.
More xylitol would be my suggestion - since it fights plaque and stops it forming in the mouth.
Spiffies tooth wipes are an idea - expensive - but another way to get to clean teeth with xylitol.
My daughter makes a solution of xylitol in water and thickens it with Thickit-2 and then dispenses a teaspoon of this as "dessert" at the end of meals.
Any idea will work - but you need about 5 exposures a day and about 1-2 teaspoons a day to stop plaque forming on teeth.
I am happy to offer more suggestions.
I would NOT suggest any kind of bleach or baking soda - since this takes away the natural protection - and that may have happened with the Oral B tooth gel - I am not familiar what it contains.