I created an app to clean the open with menu. You can download it here and find more information about this situate and the underlying process here. Hope this helps.

CleanOpenWith is an application I created to clean the Open With… menu.

CleanOpenWith is open source and free. The application automates these steps:

1. Open Terminal: Applications / Utilities / Terminal.app

2. Type in the following command :

    /System/Library/Frameworks/CoreServices.framework/Versions/A/Frameworks/LaunchServices.framework/Versions/A/Support/lsregister -kill -r -domain local -domain system -domain user
   

3. Wait for that command to complete

4. If no error then proceed to the last step, restarting Finder

5. Restarting Finder does not require you to reboot your Mac. Simply press Control + Option while clicking on the Finder icon in the Dock, select Relaunch and you are set!