Add this to your ~/.bashrc

# Quick way to rebuild the Launch Services database and get rid

of duplicates in the Open With submenu.

alias fixopenwith=/System/Library/Frameworks/CoreServices.framework/Frameworks/LaunchServices.framework/Support/lsregister -kill -r -domain local -domain system -domain user

Then run:

$ fixopenwith

From your terminal.

Thanks Getting rid of Open With duplicates – All this for the tip!