I thank Craig Smith for his post about fixing stripped screw holes.
I especially appreciated the tip about dripping some CA glue into them!

Additionally, though, if you want to prevent such stripping, it is
helpful to put the screws back where they came from (particularly
important on Steinway action rails).  One technique might be to draw
a "map" on, and then puncture little slits into, the bottom of an
upside-down empty Kleenex tissue box using the point of a box-cutting
blade.  The slits will hold the screws better than round holes created
with an ice-pick or such.

Then, draw an identical "map" onto the bottom of a second box, slitting
it as well, and as you take the screws from box #1 and polish them on
your fine wire-wheel, put them into their proper places in box #2.
You can also then spray their heads with lacquer, to thwart corrosion,
if you are in an area with high humidity.

As for plugging: while the "official" method is to drill a hole sideways
against the original path of the screw, and plug it with a dowel, this
leaves an unsightly repair and is usually not needed.  But dowels from
the lumber yard might not hold well (regardless of wood type) or endure
repeated unscrewings, if shoved down the original screw hole with a dab
of glue on them.

So I like using bamboo shish kebab skewers for this.  Several sizes
are sold in many grocery stores (though not usually all in the same
place: you need to look down every aisle!) and I believe that the
extremely tough and fibrous structure of bamboo holds the screw threads
better.

(These bamboo skewers also make inconspicuous dowels to hold soundboards
and ribs together, after initially gluing them while clamped with wire
soundboard clamps or self-threading sheet metal screws, and then
drilling out the repair to the diameter of the skewer.  And, as an
added benefit, the natural "fluting" on the sides of the bamboo hold
a nice supply of glue!)

Gordon Stelter