I am not sure about that. Probably won't help if it is too much clogged.
It is usually recommended to not drive cars for short distances because the cat won't reach the desired temperatures. It makes it more likely to get clogged.
So it is better to prevent clogging than to repair it.
There is a thing called italian tune-up. (google for more info)
You basically run a warmed up car at high rpm (~4000+) for 10-15 minutes, often reaching the redline.
It is supposed to clean the carbon deposits in the combustion chamber and the exhaust system.
Try to do it around the time you do an oil change.