We have been contacted by some school authorities who have started sterilising trumpet mouthpieces in solutions such as sterilising fluids designed for babies’ bottles. We would never recommend this! These solutions are mostly based on sodium hypochlorite – i.e. bleach.
Bleach will seriously damage the silver plating of a mouthpiece and should never be used. Sodium hypochlorite is a strong oxidant and will cause the silver to tarnish very rapidly. In addition, it will generate sodium hydroxide which will etch into the silver and cause pitting,