i've tried ballistol on mine in the past. wood grips tho. works fine, but tarnishes the brass* & gives it a not unpleasant glossy patina. to me it smells nice, but some don't like the aroma. i have a bit of trouble finding it here in the UK, so i use plain mineral oil (baby oil) for just about everything. (sadly, it refuses to take the dog for a walk)
*-ballistol was compounded to also remove copper fouling from rifles, so it will attack brass a bit. it's also anti-septic for wounds, softens your skin, it's edible, was used to treat ulcers, skin & foot fungus, and is an all -around do everything snake oil...it would walk the dog if i let it, but it can't grab the leash yet - i'm working on that.
from ballistoluk.co.uk
"In 1874, Friedrich Wilhelm Klever, an attorney with interest in economy, founded the Klever Company" in Cologne, Germany. He began producing oils and greases from coal and eventually bought a coal mine so he would not run out of raw materials. At the turn of the century the imperial German Army (the Wehrmacht) began to look for an all-around oil. The idea was to maintain the metallic parts of the soldier's rifle but also to protect the wooden stocks and his leather gear. The soldier was to use the same oil for the treatment of minor wounds, sores and scratches. Friedrich's son, Dr. Helmut Klever, had become a professor of chemistry at the Technical University of Karlsruhe. He set out to develop what the Army wanted. In 1904 he succeeded to produce a special oil which he named BALLISTOL, from the word ballistic and the Latin word for oil, 'oleum'. Thus the descriptive meaning of the word BALLISTOL is: ballistic oil. It soon became obvious that the new wonder Oil had truly amazing capabilities. The Army tested it and adopted it in 1905 and it stayed in use until 1945. But the word had spread and within a decade hunters, boaters, motorists, hikers, mountaineers and outdoorsmen in Germany, Austria and Switzerland convened to the new miracle oil.
"
p.s. - it's also water miscable, can be applied in the rain, mixed with water and sprayed and will continue to protect from corrosion and rusting. a real miracle oil unlike the poisonous stuff touted nowadays like the subject oil of this thread.