I have Shimano SLX shifters I will be using on my expedition bike. Shifters have a little bit of grease in them that keeps them working smoothly. However at the extreme colds of Antarctica the grease can get very viscous which could make the shifters not work. So I will be replacing the grease in the shifters with Lubriplate mag 1 grease.
First I spray in a generous amount of degreaser to loosen up the grease. Then I rinsed the shifters in water. I don't want the water corroding things so I spray some alcohol in the the shifter, and then blow in dry with my compressor.
While I am working with the shifters I also change the switch on the shifter to make it work with a double crank.
And now my shifters are ready to go to Antarctica.