For rust I like to use, Evapo-Rust used it on motorcycle parts and many others.
As far as i know it will not damage other material and its very safe. But make sure the part that needs to be cleaned stays submerged.
It's all about owners responsibility, keep them on a leash. I have two pitts, one of them a 7month old pup that also likes to play..yet his barking sounds very mean that scares strangers. Both of them I keep on a leash.
From a police point of view, better be safe than sorry. But I will be mad as well if that happens to me (about to submit my LTCH app) just moved from IL so i only have a FOID :(
I was the platoon firing guinea pig, went to every range they had and was even lucky to go to the German range (got silver)...of topic.
I didn't have to carry the 60 or 240 but prefer to shoot the 240.