This section is from the book "Materia Medica And Therapeutics Inorganic Substances", by Charles D. F. Phillips. Also available from Amazon: Materia medica and therapeutics.
In aphthous conditions and unhealthy ulcerations about the gums, palate, or tonsils, gargles containing the chlorate or permanganate are very good (v. p. 283). In diphtheria, both these salts have proved of great service (Ranking, i., 1865). A useful proportion of the permanganate for local application is about 10 gr. to the pint of water.