[32phil]

I use Evapo Rust in mine to clean lock parts and column drop parts.
It removes rust and corrosion from ferrous metal rusty parts very quickly.
For brass parts they will be discolored slightly as well.
Doesn't hurt chrome, actually cleans it up nicely.
For pot metal you must pay attention as it will eat them mercilessly.
It's best to inspect pot metal parts every 5-10 minutes to judge the progress and remove from the cleaner if necessary.