When I mentioned silicone grease as a sealant I was not recommending
it as a substitute for proper rebuilding.  I was just suggesting that
diluted silicone grease can be used to seal pouches.  Others have
suggested that pouch well leaks may be more of a problem than the
pouches themselves leaking.  There are varying opinions as to what
manufacturers did or did not do originally to seal pouches.

Although there was still some good pouch leather available the last
time I bought some, it is probably true that the vast majority of
pouch leather today is both thicker and more leaky than what was
available commonly in the heyday of player manufacturer.  For this
reason it can be useful to seal today's pouch leather and a sealant
that provides the long lasting seal (if actually necessary) with the
least stiffening of the pouch is probably the best.

If a previous rebuilder did a decent job and did seal the pouch
wells carefully but used leaky pouches and did not seal them, it is
conceivable that sealing them with diluted silicone grease might help.
If a test on a few pouches does not result in a reasonably tight seal
it would be obvious that leaks were elsewhere.

Spencer Chase