I've finally found an answer for EO Jones. He was our form teacher in 1952-53 but he also liked to reminisce about his time in India - in the Indian Army I suppose? He told us one day that he didn't clean his teeth with a toothbrush; he thought that tooth brushes damaged gums. I don't recall him telling us what he did clean his teeth with but he did tell us about the way the 'Natives' in India cleaned their teeth - they used twigs. He went on to say that he never could discover what sort of twigs they were or where they came from.
I have the answer! I've recently been reading a travel book by Paul Theroux (The Great Railway Bazaar) and he tells how the Tamils teeth are prominent "and glisten from repeated scrubbing with peeled green twigs". The best toothbrush twigs are found in the forests of Madhya Pradesh and are sold in bundles bound like cheroots at the stations in the province.
Too late for EO now I suppose