Your question is sort of like, "how do I keep my
unpainted steel car from rusting?" Answer: in the long run, you can't.
Originally Posted by
nfmisso
Rebuild your wheels with nickel plated brass nipples - any choice leaving the alloy nipples in place is not going to be very effective.
+1 I bought a used wheelset very cheap that needed some truing and the spokes were way too loose. Aluminum nipples were all seized up. I tried lubricating to get them to move. No dice. Broke spokes trying to true the wheels. Cut all the spokes, threw them in the trash, and rebuilt with double butted stainless steel spokes and brass nipples like I always do. They're worth the extra few grams per wheel.