I made two posts, one at the beginning of the summer that explained how the sweat reacts to certain metals.
Gold, Platinum and Stainless Steel are "pervious" to salt--it won't tarnish, rust or stain.
Other metals oxidize with the salt causing staining, rusting and even discolorment.
As for things like cowhide, leather and such...I avoid those because I know they will turn to "jerky" and dry up.
My sword handle is wrapped in a cotton-based thread so its got a whitish-grey coloring to it. I intend to avoid such metals as copper and aluminum, but it may be tricky.
I stopped wearing a watch until I found that the stainless ones (diver's watches) can handle my sweat...I just run it under water frequently so the buttons don't get clogged and malfunction.
Keyboards...LOL...I gotta clean mine at work! I found that putting a keyboard cover on the keyboards causes them to last longer...just last night I was using the "undprotected" keyboard and one of the letters stopped working..probably cause some of the salt had creeped into the board causing a poor connection.
BTW, (Most) plastics are ok with sweat, but I don't think too many things made of wood are very good..so that would be a caution to make if you are dealing with wood.