I’m not sure how many people have this problem, but I’ve found that sometimes Open-with context menu on my Mac gets filled with duplicates.  I’ve found this is usually a result of backing of my computer, mainly bootable copies.  So I made this little Automator app that fixes the problem.  I’m making it freely available to anyone who needs it.  Let me know if you find it useful.

https://www.dropbox.com/sh/jdld3jitktmelo7/XVd4JLT3uR