I have used campy chorus ergo on at least four bikes, and I have always had problems with the thumb shifters freezing up and preventing the pawl from engaging the ratchet. I've also used bias tape (cloth tape used for edging in sewing) because it gave a good grip, is cheap, and can be applied very neatly. It does absorb sweat, and I learned to apply plastic electrical tape underneath which also has the benefit of holding cables in place very securely.
Finances have been a problem for some time and life style has changed, so I haven't been riding at the previous level and have a litespeed that hasn't been used since about 05. Finally decided that I needed to bite the bullet and get it working again. Basic problem was possible corrosion in cables and the thumb shifter on the one of the brifters doesn't engage. I found some NOS record 9 speed brifters and just decided to buy them rather than refurbishing my old units. Of course the handle bars need to be replaced because salt has corroded the bars near the clamps where they weren't protected by the plastic tape.
My first bright idea is to apply a urethane varnish to the bars before installing the new levers and tape. But that doesn't address the issue of sealing the thumb shifter. I'm sure that I will need to spend a little more effort to cleaning the bars and regular maintenance after rides. While sd40 may be red green's companion to duck tape, the idea of just flushing with the hydrophilic lubricant leaves me a little cold because of the possibility of washing out lubricating grease or other unintended consequences. I worked on a 3 speed that had frozen pawls because the kid wash washing his bike off with a garden hose.
Recommended regular preventive maintenance without tearing everything apart? Maybe a dollop of grease on the thumb shifter pivot and index gear?