Strings: To clean or not to clean?

There are 2 school of thoughts when it comes to string cleaning:

1. Don't clean: Strings are expandable. Play your guitar, leave it be, if the strings rust, you can always get new strings.
2. Clean: After each play, you leave dirt & grime on your strings. If you don't clean them, you'll be coming into contact with them the next time you play- this will affect feel.

Yes, strings are expandable, you'd be replacing them anyway but having dirt left behind for you to deal with is a NO for me. The very least that I do after each play is to wipe my strings down. However, I prefer using cleaning fluid.