Replying to Rust on Edges ???

So i think what happened was some ice or packed snow melted off my bindings and some water must have touched the edges.... So i had a couple very small spots of rust on my edges. I basically wiped them off, but noticed they still had a dark stain from where the rust was. So I know rust is never good. but is it really bad?

How can i prevent this in the future? because I dryed them off nice, except i couldn't get some of the snow out of the cracks in my bindings... should i put a hair drier on them???