I'm on month #3 of having replaced everything and once again a slow
drip is developing. Someone came up with a few other suggestions. What
do you guys think?

1. Try using "no-rotate" or swiveling washers. Anyone have any luck
with these? Any installation tips would be greatly appreciated.

2. Try stainless steel seats. I noticed that after only a few months
of use, a brand new seat has almost a sandpaper like tarnish/coating to
it.
Would stainless seats prevent this? I think this may be causing the
washer to fail so quickly. Does anyone know of a supplier for
stainless steel valve seats?

As long as the seat is undeformed or unworn, the faucet should shut off. Did
you use pipe joint compound on the seat threads when you replaced the seat?
(should have) Is the seat fully seated in its socket? Also, faucet needs to
be very gently shut off, especially when new. Folks who "crank" the faucet
off will quickly abrade, distort, and ruin the new washer. Faucet should be
dripless with just a two-finger shutoff torque.