To wipe the cache on a droid razr that is NOT rooted:
1. Turn the phone off
2. Press and hold the power button and that vol up AND vol down keys all at the same time untill it loads into the screen where you can select "recovery"
3. Use the vol down key to highlight "recovery" then use the vol up key to select it
4. Wait for it to boot up (not pressing anything) untill you see an Android and a ! Inside of a triangle.
5. Once that screen appears, press the vol up and vol down key at the same time
6. It should load the recovery menu, press the vol down key to get down to "wipe cache" then use the power key to select it
7. When it is done, go to "reboot system now" and select it with the power key.
And thats it, no root needed
Sent from my DROID RAZR