[eximius]

I also tend to think of thermite before uncleanliness when I hear rust. Rust is just iron oxide, not anything dirty.

[SilasX]

When I hear "rust", I get images of rusty pipes, old rusty nails, faucets where the water is tainted with rust, and people's skills getting rusty. I feel disgust, and it's why I didn't feel particularly eager pursuing it further.