1993 Camry LE with 290 K miles...

I've read posts where cleaning the IAC valve with Throttle Body cleaner can screw it up...Is this true?

I have used carb cleaner in the past on the IAC valve to clean it and I do still have a rough idle...I've done everything in the book that I've read on this forum to address my rough idle problem as much as possible. I do still get great MPG on this old.

Maybe it's time i go to the junkyard and get one used at a cheap price in good shape...anything I should look for upon inspection of a used IAC If i decide to take on this endeavor to ensure the used one is in good shape?

The IAC valve seems fairly easy to replace with the naked eye. It would be my first time, but it seems easy to get to and replace unless there are some tips you guys can give me to watch out for.

thanks!
Brian