Topmusicanswers
Once every few months, the instrument should be cleaned internally, by running warm soapy water through it (hold the valves down whilst pouring water into the bell). Rinse thoroughly with cold water and then allow to dry. Do not use hot water as this may affect the lacquer.
Can you submerge a French horn?
Submerge the horn completely in water and press down all valves to open them (just a couple of times, you don't need to keep them down.) Leave the horn for an hour to around three hours (only if it is an instrument that hasn't been bathed in a very long time, or if the valves are stuck down.)
