there's a couple of missing stars in that command between the slashes.
That said, this didn't replace the icon for me.
I needed to touch the app folder as well for the update to work
touch /Applications/Sublime\ Text.app
rm /var/folders/*/*/*/com.apple.dock.iconcache;killall Dock
Note: if you do replace it, you probably will need to kill your dock, and clear the icon cache; here's a good command to do so:
rm /var/folders///*/com.apple.dock.iconcache;killall Dock