The "stuff" is kept in a six sided, 5" thick, closely mesh re-barred concrete room with a steel vault door. This has a separate Halon fire system and heating / air system holding 70 degrees F year round. As a result there is very, very little dust or humidity, which in the South can be a real problem.
The more valuable stuff is Renaissance waxed, wood, metal and leather. On the rest of the metal I use Balistol, very thin. Stocks, pistol grips, etc, get a very light rub with Kramer's Best.