Tap Ten Times to Clear Cache?

Apple rarely posts anything here, and when they do, it's little more than links to support articles.

And what does using the home button to "manage" the phone have to do with something as ridiculous as tapping an icon 10 times to magically clear a cache?

You are not talking to Apple. This is a user forum.

As for is it true... um.. no.

Randy Zeitman wrote:

I know but Apple can reply here too.

Yes, but they won't.

(How do you know it's false?)

The same way I know that you can't charge your phone by putting it in a microwave...

Doing this in iTunes or the App Store will effectively just reload these. I don't think this works at all in the other apps you listed. It has little value and I haven't seen it fix anything that force closing and relaunching the app won't fix (which is what most people do anyway when an app isn't quite working right). If anything, it's just a cool little trick that might save you from needing to force close and relaunch iTunes or the App Store in the event that something isn't quite working right.