Shouldn't there be an -f after the -r?
Don't forget the /Applications at the end.
This was copied from MacOSXHints, and it worked for me...
/System/Library/Frameworks/ApplicationServices.framework/Versions/A/Frameworks/LaunchServices.framework/Versions/A/Support/lsregister -kill -r -f -domain local -domain system -domain user "/Applications"
Scroll down a little further.Code:/System/Library/Frameworks/ApplicationServices.framework/Versions/A/Frameworks/LaunchServices.framework/Versions/A/Support/lsregister -kill -r -f -domain local -domain system -domain user "/Applications"
I've had problems with the example you posted.
Did you want to get rid of all of the adobe droplets from the menu as well. Then look at this