John Taber, I like that Teflon spray lubricant, too.  I  have a little
can in my tool box.  I would like to add to the possible uses: stuck
sliding doors, air motor crankshafts (avoid spraying the tuning pins),
sticking keys where friction is the problem; [use] like graphite/alcohol
paste, almost anywhere there is wood and felt and "problem friction".

Graphite is time honored and "tried and true" and historically accurate,
but it has disadvantages.  As neat as I try to be with it, it just
finds a way to stain my good clothes and the customer's white carpet.

The disadvantages of the Teflon spray (which I know of) are unhealthy
fumes (use in ventilated room) and the possibility of getting it on the
piano's finish (it will eat into it).  One time I pressed the spray
button and it dribbled down the side of the can instead of forward,
right onto the finish.

Sometimes an air motor needs to be re-lapped with sand paper and a
glass block.  Sometimes all the air motor needs is a quick spray and
that un-useable piano has a nice smooth, steady tempo.  Sometimes we
fall in love with some "cool new product" and the temptation is to look
for any excuse to use it.  I am not close to ready to part with my
graphite; I use it very often as well.

Bill  Maguire