Honestly you'd probably have to run a can every single day to keep those valves clean. But if it makes you feel better, use it every time you do an oil change (every 4K). I don't think it's too to help much, but if it makes you feel better do it.
That's the key with vehicle maintenance...if it makes you feel better? Do it. Honestly. If you plan on keeping a car a long time you have to do things that you believe in/makes you feel good. It keeps you motivated.
Luckily for you the 2.4L engine is pretty easy to remove the intake on (if I remember) and you could manually clean the valves every 40,000-50,000 miles if you really want to.