One of the first things I do upon receiving new figures is clean the surface area of dust and dirt. After hearing of several methods, I have settled on using a metal protector, such as Armor All. I have never had any adverse effects from using it. Besides cleanng, you get a nice luster when buffing, if you have good paint. It can also be used in cleaning rubber and vinyl figures and vehicles. I generally spray a liberal amount on a q-tip and go to cleaning. If the figure is really dirty, I spray the entire figure and then q-tip it dry. Q-tips do well in crevices and are non abrasive. After I get a good cleaning, I inspect the figure under a bright light using a magnifying glass. I look for cracks, damage, or casting variations.
There is no greater enemy to a collector than lead disease, more commonly known as "lead rot" or "lead cancer". Easily identified by the white or grey residue or powder. Corrosion may be so severe as to completely consume the piece. There are many culprits to this condition, but some of the leading causes are high temperatures in an oak cabinet which forms high levels of acetic acid, stagnant air in oak cabinets which form high levels of acetic acid, even if the figures are not touching the wood, high humidity in the cabinet, immersion in water, such as New Orleans flood. A rule of thumb is, hard woods emit higher levels of acetic acid, but all wood emits some acetic acid, so a non wood cabinet is the best storage solution.
Now for the restoration process for lead figures, use a mixture of 50 percent pure gum spirits of turpentine (not substitue) and 50 percent highly refined medicainal mineral oil. Save your mixture in a tupperware bowl with a sealable lid to re-use. You need some Q-tips for application. Brush off the affected figures, scrape away the rotten areas or powder, apply the solution, gently wipe off excess, and let the figure air dry for seven days. The same hollowcasts where the lead rot sometimes begins inside the figure.