Interesting that you mentioned G96... somewhere along the line, I'd guess 35 or 40 years ago I began using "G96 Triple Action Gun Treatment" with my firearms for light cleanup (bore, actions - including gas rings/tube in shotguns, etc., and particularly when a really nasty-to-use bore solvent like "Shooters Choice" wasn't warranted for bore), as well as exterior wipedown before placing back in cabinet or closet, etc. Rarely or never had any surface corrosion due to handling or otherwise. Still use it to this day for light cleanups/touchups of handguns and longarms, though I will use more thixotropic, heavier final lubes for rails, etc., as G96 is very low viscosity product, of course, due to its "triple-action" properties. Another interesting product I continue to use for firearms when I do need a more thixotropic, clingy property (though not heavy like the typical greases), is "Fluid Film" ("FF"). I'll clean up the weapon w/G96, removing excess, and finish with Fluid Film on exterior metals, polymers and wood (great for wood stocks, and doesn't degrade finishes... you can even use it on leather, unlike most petroleum based products... FF is not petroleum based, but derived from - believe it or not - sheep's wool), and then run a barely FF-dampened patch through the bore, plus the tiniest little amounts on rails, slides, connectors, etc., on (for instance) my Glocks. These two products, alone, can just about do everything in gun cleanup/pre-storage, except for perhaps removing heavy copper or lead fouling in a bore, which usually requires more caustic chemicals. (I do not believe in doing frequent heavy, caustic solvent bore cleaning when not needed.) If you let the G96 soak the bore for a while before brushing/patching, you'll remove most powder residue and even some of the copper fouling. I've used these procedures routinely "with nary a problem" for many a year, now. Thanks...
