Re: so, my friend has really sweaty palms...
One, he may have a dermatological condition that could be treated. I know that there is a product on the market. He should also make sure that he washes his hands before each playing session.
Two, covered pickups are a must. Using a dab of dielectric grease can protect switches.
And three, probably the most effective thing is simply wiping down the guitar with a damp rag and then buffing it with a soft dry cloth. A light polish with a Carnauba wax product will help protect the finish.
A friend of mine was an auto mechanic, working all day in oil, gas and solvents. I finally had to ban him from playing my guitars...he could completely kill a new set of strings in 3.2 seconds.
In this case though, the sweaty palm issue is only part of the problem. This guitar is not being maintained properly.
Bill