My '46 Martin Committee came with an original owner's manual. In this manual it states: If... the valves tend to "slow down" after you've played a while, remove the first valve slide and pour in a little oil. This oil acts as a cleansing agent rather than a lubricant. Has any one heard this before? Is it true? Here is the other part of the instructions that is unique: ...to keep it thoroughly clean inside and outside... Hold the bell under a top of clear running water, neither too cold or too hot, until the instrument is full. Work the valves while blowing the water out of the bell, thereby flushing off the pumps, and then dry the outside of the horn. Again, why would one do this... does it improve the valve actions... and why?