autorx will definitely help your engine's performance and should be a part of any tune-up effort on a car that old, however it may or may not solve your rough idle problem.
Cleaning the throttle body is a good idea, and is best done manually. Here are some instructions:
Any fuel injector cleaner in a bottle may also help your idle, as will replacing the idle speed control, egr valve, and checking for any loose or cracked vacuum lines. Improving a rough idle on an older engine is a bit of guesswork, but between these items and what you've done already your idle should improve.
