I have also been ordering a bunch of those top row encoders because they were starting to behave unreliably. I gave up on replacing them after the first one, because desoldering was a pain, and i am not very handy with the heat gun. Anyway, out of laziness i tried “Kontakt Chemie Tuner 600″. Just removed the Encoder Knobs and shot right between the axle and the encoder housing.
I don’t believe in wonders, and i wasn’t sure if it’s a good idea to spend 16€ on a magical liquid. Anyway, i wouldn’t post this, if the BCR wasn’t working nicely for over half a year now. Of course i am aware that this doesn’t solve the malfunctioning button issue.
Looking at the average price tag for these things at the moment… i would say that pretty much every measure is worth it to repair the hardware.