Rem Oil, lots and lots of Rem Oil.
I live in southern Georgia near the coast, so I sweat a fair amount too.
Heck, I'll go so far as to say that factor directly influenced my decision to go with a Glock for daily carry.
Definintly removed your piece from it's holster before you go to bed, wipe it down, and let the holster air out.
I'm not in a position to worry about small children, so I have a rag on my night stand dedicated to this procedure.
Also, I wipe down the weapon and the magazine every night and coat it lightly in oil.
And +1 to the using shoe polish on the holster. I have a Tagua inside the waist band holster that I wipe down once a week with plain old regular black Kiwi polish.